diff --git a/src/tint/cmd/tint/main.cc b/src/tint/cmd/tint/main.cc
index c0bf14c..24ef2fd 100644
--- a/src/tint/cmd/tint/main.cc
+++ b/src/tint/cmd/tint/main.cc
@@ -1209,8 +1209,10 @@
 
 /// Generate IR code for a program.
 /// @param program the program to generate
+/// @param options the options that Tint was invoked with
 /// @returns true on success
-bool GenerateIr([[maybe_unused]] const tint::Program& program) {
+bool GenerateIr([[maybe_unused]] const tint::Program& program,
+                [[maybe_unused]] const Options& options) {
 #if !TINT_BUILD_WGSL_READER
     std::cerr << "WGSL reader not enabled in tint build" << std::endl;
     return false;
@@ -1220,7 +1222,8 @@
         std::cerr << "Failed to build IR from program: " << result.Failure() << "\n";
         return false;
     }
-    std::cout << tint::core::ir::Disassemble(result.Get()) << "\n";
+    options.printer->Print(tint::core::ir::Disassemble(result.Get()));
+    options.printer->Print(tint::StyledText{} << "\n");
     return true;
 #endif
 }
@@ -1362,7 +1365,7 @@
 
 #if TINT_BUILD_WGSL_READER
     if (options.dump_ir) {
-        GenerateIr(info.program);
+        GenerateIr(info.program, options);
     }
 #endif  // TINT_BUILD_WGSL_READER
 
@@ -1474,7 +1477,7 @@
             success = GenerateGlsl(program, options);
             break;
         case Format::kIr:
-            success = GenerateIr(program);
+            success = GenerateIr(program, options);
             break;
         case Format::kNone:
             break;
diff --git a/src/tint/lang/core/ir/binary/roundtrip_fuzz.cc b/src/tint/lang/core/ir/binary/roundtrip_fuzz.cc
index 32886de..ccc7a9c 100644
--- a/src/tint/lang/core/ir/binary/roundtrip_fuzz.cc
+++ b/src/tint/lang/core/ir/binary/roundtrip_fuzz.cc
@@ -46,8 +46,8 @@
         return;
     }
 
-    auto in = Disassemble(module);
-    auto out = Disassemble(decoded.Get());
+    auto in = Disassemble(module).Plain();
+    auto out = Disassemble(decoded.Get()).Plain();
     if (in != out) {
         TINT_ICE() << "Roundtrip produced different disassembly\n"
                    << "-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-\n"
diff --git a/src/tint/lang/core/ir/binary/roundtrip_test.cc b/src/tint/lang/core/ir/binary/roundtrip_test.cc
index 19344f1..9d8b368 100644
--- a/src/tint/lang/core/ir/binary/roundtrip_test.cc
+++ b/src/tint/lang/core/ir/binary/roundtrip_test.cc
@@ -47,7 +47,7 @@
 class IRBinaryRoundtripTestBase : public IRTestParamHelper<T> {
   public:
     std::pair<std::string, std::string> Roundtrip() {
-        auto pre = Disassemble(this->mod);
+        auto pre = Disassemble(this->mod).Plain();
         auto encoded = Encode(this->mod);
         if (encoded != Success) {
             return {pre, encoded.Failure().reason.Str()};
@@ -56,7 +56,7 @@
         if (decoded != Success) {
             return {pre, decoded.Failure().reason.Str()};
         }
-        auto post = Disassemble(decoded.Get());
+        auto post = Disassemble(decoded.Get()).Plain();
         return {pre, post};
     }
 };
diff --git a/src/tint/lang/core/ir/disassembler.cc b/src/tint/lang/core/ir/disassembler.cc
index c31cad8..ff7b390 100644
--- a/src/tint/lang/core/ir/disassembler.cc
+++ b/src/tint/lang/core/ir/disassembler.cc
@@ -69,6 +69,7 @@
 #include "src/tint/utils/macros/scoped_assignment.h"
 #include "src/tint/utils/rtti/switch.h"
 #include "src/tint/utils/text/string.h"
+#include "src/tint/utils/text/styled_text.h"
 
 using namespace tint::core::fluent_types;  // NOLINT
 
@@ -87,7 +88,7 @@
 
 }  // namespace
 
-std::string Disassemble(const Module& mod) {
+StyledText Disassemble(const Module& mod) {
     return Disassembler{mod}.Disassemble();
 }
 
@@ -95,7 +96,7 @@
 
 Disassembler::~Disassembler() = default;
 
-StringStream& Disassembler::Indent() {
+StyledText& Disassembler::Indent() {
     for (uint32_t i = 0; i < indent_size_; i++) {
         out_ << " ";
     }
@@ -103,9 +104,9 @@
 }
 
 void Disassembler::EmitLine() {
-    out_ << std::endl;
+    out_ << "\n";
     current_output_line_ += 1;
-    current_output_start_pos_ = out_.tellp();
+    current_output_start_pos_ = static_cast<uint32_t>(out_.Length());
 }
 
 size_t Disassembler::IdOf(const Block* node) {
@@ -159,10 +160,15 @@
 }
 
 Source::Location Disassembler::MakeCurrentLocation() {
-    return Source::Location{current_output_line_, out_.tellp() - current_output_start_pos_ + 1};
+    return Source::Location{
+        current_output_line_,
+        static_cast<uint32_t>(out_.Length()) - current_output_start_pos_ + 1,
+    };
 }
 
-std::string Disassembler::Disassemble() {
+const StyledText& Disassembler::Disassemble() {
+    out_.Clear();
+
     for (auto* ty : mod_.Types()) {
         if (auto* str = ty->As<core::type::Struct>()) {
             EmitStructDecl(str);
@@ -177,7 +183,7 @@
     for (auto& func : mod_.functions) {
         EmitFunction(func);
     }
-    return out_.str();
+    return out_;
 }
 
 void Disassembler::EmitBlock(const Block* blk, std::string_view comment /* = "" */) {
diff --git a/src/tint/lang/core/ir/disassembler.h b/src/tint/lang/core/ir/disassembler.h
index 6b6f7c6..df20534 100644
--- a/src/tint/lang/core/ir/disassembler.h
+++ b/src/tint/lang/core/ir/disassembler.h
@@ -33,7 +33,6 @@
 #include "src/tint/lang/core/ir/binary.h"
 #include "src/tint/lang/core/ir/block.h"
 #include "src/tint/lang/core/ir/block_param.h"
-#include "src/tint/lang/core/ir/call.h"
 #include "src/tint/lang/core/ir/if.h"
 #include "src/tint/lang/core/ir/loop.h"
 #include "src/tint/lang/core/ir/module.h"
@@ -42,6 +41,7 @@
 #include "src/tint/utils/containers/hashmap.h"
 #include "src/tint/utils/containers/hashset.h"
 #include "src/tint/utils/text/string_stream.h"
+#include "src/tint/utils/text/styled_text.h"
 
 // Forward declarations.
 namespace tint::core::type {
@@ -52,7 +52,7 @@
 
 /// @returns the disassembly for the module @p mod
 /// @param mod the module to disassemble
-std::string Disassemble(const Module& mod);
+StyledText Disassemble(const Module& mod);
 
 /// Helper class to disassemble the IR
 class Disassembler {
@@ -80,12 +80,9 @@
     explicit Disassembler(const Module& mod);
     ~Disassembler();
 
-    /// Returns the module as a string
+    /// Returns the module as a styled text string
     /// @returns the string representation of the module
-    std::string Disassemble();
-
-    /// @returns the string representation
-    std::string AsString() const { return out_.str(); }
+    const StyledText& Disassemble();
 
     /// @param inst the instruction to retrieve
     /// @returns the source for the instruction
@@ -190,7 +187,7 @@
         Source::Location begin_;
     };
 
-    StringStream& Indent();
+    StyledText& Indent();
 
     size_t IdOf(const Block* blk);
     std::string IdOf(const Value* node);
@@ -221,7 +218,7 @@
     void EmitInstructionName(const Instruction* inst);
 
     const Module& mod_;
-    StringStream out_;
+    StyledText out_;
     Hashmap<const Block*, size_t, 32> block_ids_;
     Hashmap<const Value*, std::string, 32> value_ids_;
     Hashset<std::string, 32> ids_;
diff --git a/src/tint/lang/core/ir/ice.h b/src/tint/lang/core/ir/ice.h
index 40ef1dd..6487cc3 100644
--- a/src/tint/lang/core/ir/ice.h
+++ b/src/tint/lang/core/ir/ice.h
@@ -31,6 +31,7 @@
 #include "src/tint/lang/core/ir/disassembler.h"
 
 /// Emit an ICE message with the disassembly of `mod` attached.
-#define TINT_IR_ICE(mod) TINT_ICE() << tint::core::ir::Disassembler{mod}.Disassemble() << "\n"
+#define TINT_IR_ICE(mod) \
+    TINT_ICE() << tint::core::ir::Disassembler{mod}.Disassemble().Plain() << "\n"
 
 #endif  // SRC_TINT_LANG_CORE_IR_ICE_H_
diff --git a/src/tint/lang/core/ir/transform/direct_variable_access_wgsl_test.cc b/src/tint/lang/core/ir/transform/direct_variable_access_wgsl_test.cc
index 1270cf7..374d980 100644
--- a/src/tint/lang/core/ir/transform/direct_variable_access_wgsl_test.cc
+++ b/src/tint/lang/core/ir/transform/direct_variable_access_wgsl_test.cc
@@ -38,6 +38,7 @@
 #include "src/tint/lang/wgsl/writer/ir_to_program/ir_to_program.h"
 #include "src/tint/lang/wgsl/writer/raise/raise.h"
 #include "src/tint/lang/wgsl/writer/writer.h"
+#include "src/tint/utils/text/styled_text.h"
 
 namespace tint::core::ir::transform {
 namespace {
@@ -80,7 +81,7 @@
             return "DirectVariableAccess failed:\n" + res.Failure().reason.Str();
         }
 
-        auto pre_raise = ir::Disassemble(module.Get());
+        auto pre_raise = ir::Disassemble(module.Get()).Plain();
 
         if (auto raise = wgsl::writer::Raise(module.Get()); raise != Success) {
             return "wgsl::writer::Raise failed:\n" + res.Failure().reason.Str();
@@ -89,15 +90,15 @@
         auto program_out = wgsl::writer::IRToProgram(module.Get(), program_options);
         if (!program_out.IsValid()) {
             return "wgsl::writer::IRToProgram() failed: \n" + program_out.Diagnostics().Str() +
-                   "\n\nIR (pre):\n" + pre_raise +                       //
-                   "\n\nIR (post):\n" + ir::Disassemble(module.Get()) +  //
+                   "\n\nIR (pre):\n" + pre_raise +                               //
+                   "\n\nIR (post):\n" + ir::Disassemble(module.Get()).Plain() +  //
                    "\n\nAST:\n" + Program::printer(program_out);
         }
 
         auto output = wgsl::writer::Generate(program_out, wgsl::writer::Options{});
         if (output != Success) {
             return "wgsl::writer::IRToProgram() failed: \n" + output.Failure().reason.Str() +
-                   "\n\nIR:\n" + ir::Disassemble(module.Get());
+                   "\n\nIR:\n" + ir::Disassemble(module.Get()).Plain();
         }
 
         return "\n" + output->wgsl;
diff --git a/src/tint/lang/core/ir/transform/helper_test.h b/src/tint/lang/core/ir/transform/helper_test.h
index 84e0f7e..ef8e375 100644
--- a/src/tint/lang/core/ir/transform/helper_test.h
+++ b/src/tint/lang/core/ir/transform/helper_test.h
@@ -62,7 +62,7 @@
     }
 
     /// @returns the transformed module as a disassembled string
-    std::string str() { return "\n" + ir::Disassemble(mod); }
+    std::string str() { return "\n" + ir::Disassemble(mod).Plain(); }
 
   protected:
     /// The test IR module.
diff --git a/src/tint/lang/core/ir/validator.cc b/src/tint/lang/core/ir/validator.cc
index 24d594d..c9db3d3 100644
--- a/src/tint/lang/core/ir/validator.cc
+++ b/src/tint/lang/core/ir/validator.cc
@@ -357,7 +357,7 @@
     if (disassembly_file) {
         return;
     }
-    disassembly_file = std::make_unique<Source::File>("", dis_.Disassemble());
+    disassembly_file = std::make_unique<Source::File>("", dis_.Disassemble().Plain());
 }
 
 Result<SuccessType> Validator::Run() {
diff --git a/src/tint/lang/spirv/reader/parser/helper_test.h b/src/tint/lang/spirv/reader/parser/helper_test.h
index 1aece7f..cf510d3 100644
--- a/src/tint/lang/spirv/reader/parser/helper_test.h
+++ b/src/tint/lang/spirv/reader/parser/helper_test.h
@@ -82,7 +82,7 @@
         }
 
         // Return the disassembled IR module.
-        return core::ir::Disassemble(parsed.Get());
+        return core::ir::Disassemble(parsed.Get()).Plain();
     }
 };
 
diff --git a/src/tint/lang/spirv/reader/reader_test.cc b/src/tint/lang/spirv/reader/reader_test.cc
index 20a0ebb..cd0626b 100644
--- a/src/tint/lang/spirv/reader/reader_test.cc
+++ b/src/tint/lang/spirv/reader/reader_test.cc
@@ -64,7 +64,7 @@
         }
 
         // Return the disassembled IR module.
-        return "\n" + core::ir::Disassemble(ir.Get());
+        return "\n" + core::ir::Disassemble(ir.Get()).Plain();
     }
 };
 
diff --git a/src/tint/lang/wgsl/ir_roundtrip_fuzz.cc b/src/tint/lang/wgsl/ir_roundtrip_fuzz.cc
index 3b41233..0265906 100644
--- a/src/tint/lang/wgsl/ir_roundtrip_fuzz.cc
+++ b/src/tint/lang/wgsl/ir_roundtrip_fuzz.cc
@@ -50,7 +50,7 @@
     program_options.allowed_features = AllowedFeatures::Everything();
     auto dst = tint::wgsl::writer::IRToProgram(ir, program_options);
     if (!dst.IsValid()) {
-        std::cerr << "IR:\n" << core::ir::Disassemble(ir) << std::endl;
+        std::cerr << "IR:\n" << core::ir::Disassemble(ir).Plain() << std::endl;
         if (auto result = tint::wgsl::writer::Generate(dst, {}); result == Success) {
             std::cerr << "WGSL:\n" << result->wgsl << std::endl << std::endl;
         }
diff --git a/src/tint/lang/wgsl/ir_roundtrip_test.cc b/src/tint/lang/wgsl/ir_roundtrip_test.cc
index 6573c32..ac07621 100644
--- a/src/tint/lang/wgsl/ir_roundtrip_test.cc
+++ b/src/tint/lang/wgsl/ir_roundtrip_test.cc
@@ -73,14 +73,14 @@
             return result;
         }
 
-        result.ir_pre_raise = core::ir::Disassemble(ir_module.Get());
+        result.ir_pre_raise = core::ir::Disassemble(ir_module.Get()).Plain();
 
         if (auto res = tint::wgsl::writer::Raise(ir_module.Get()); res != Success) {
             result.err = res.Failure().reason.Str();
             return result;
         }
 
-        result.ir_post_raise = core::ir::Disassemble(ir_module.Get());
+        result.ir_post_raise = core::ir::Disassemble(ir_module.Get()).Plain();
 
         writer::ProgramOptions program_options;
         program_options.allowed_features = AllowedFeatures::Everything();
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/accessor_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/accessor_test.cc
index cb5294e..0530639 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/accessor_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/accessor_test.cc
@@ -53,7 +53,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, array<u32, 3>, read_write> = var
@@ -79,7 +79,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, array<u32, 3>, read_write> = var
@@ -106,7 +106,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, array<u32, 3>, read_write> = var
@@ -134,7 +134,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:vec3<u32> = let vec3<u32>(0u)
@@ -159,7 +159,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, vec3<u32>, read_write> = var
@@ -184,7 +184,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, vec3<u32>, read_write> = var
@@ -210,7 +210,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, vec3<u32>, read_write> = var
@@ -234,7 +234,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, array<array<f32, 4>, 3>, read_write> = var
@@ -260,7 +260,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, array<array<f32, 4>, 3>, read_write> = var
@@ -287,7 +287,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, array<array<f32, 4>, 3>, read_write> = var
@@ -312,7 +312,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, mat3x4<f32>, read_write> = var
@@ -340,7 +340,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(MyStruct = struct @align(4) {
   foo:i32 @offset(0)
 }
@@ -374,7 +374,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(MyStruct = struct @align(4) {
   foo:i32 @offset(0)
 }
@@ -409,7 +409,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(MyStruct = struct @align(4) {
   foo:i32 @offset(0)
 }
@@ -447,7 +447,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(Inner = struct @align(4) {
   bar:f32 @offset(0)
 }
@@ -493,7 +493,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(Inner = struct @align(16) {
   b:i32 @offset(0)
   c:f32 @offset(4)
@@ -528,7 +528,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, array<u32, 4>, read_write> = var
@@ -551,7 +551,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, vec2<f32>, read_write> = var
@@ -576,7 +576,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, vec2<f32>, read_write> = var
@@ -602,7 +602,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, vec2<f32>, read_write> = var
@@ -626,7 +626,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, vec3<f32>, read_write> = var
@@ -650,7 +650,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, vec3<f32>, read_write> = var
@@ -682,7 +682,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(MyStruct = struct @align(16) {
   a:i32 @offset(0)
   foo:vec4<f32> @offset(16)
@@ -713,7 +713,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:vec3<u32> = let vec3<u32>(0u)
@@ -736,7 +736,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:mat3x4<f32> = let mat3x4<f32>(vec4<f32>(0.0f))
@@ -763,7 +763,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(MyStruct = struct @align(4) {
   foo:i32 @offset(0)
 }
@@ -799,7 +799,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(Inner = struct @align(4) {
   bar:f32 @offset(0)
 }
@@ -844,7 +844,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(Inner = struct @align(16) {
   b:i32 @offset(0)
   c:f32 @offset(4)
@@ -878,7 +878,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:vec2<f32> = let vec2<f32>(0.0f)
@@ -901,7 +901,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:vec3<f32> = let vec3<f32>(0.0f)
@@ -924,7 +924,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:vec3<f32> = let vec3<f32>(0.0f)
@@ -955,7 +955,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(MyStruct = struct @align(16) {
   a:i32 @offset(0)
   foo:vec4<f32> @offset(16)
@@ -988,7 +988,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %i:i32 = let 1i
@@ -1013,7 +1013,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %i:i32 = let 1i
@@ -1038,7 +1038,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %i:i32 = let 1i
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/binary_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/binary_test.cc
index 79b7366..662de7b 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/binary_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/binary_test.cc
@@ -46,7 +46,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -70,7 +70,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -93,7 +93,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -116,7 +116,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -140,7 +140,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, i32, read_write> = var
 }
 
@@ -163,7 +163,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -186,7 +186,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -210,7 +210,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -233,7 +233,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -257,7 +257,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -280,7 +280,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -304,7 +304,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -327,7 +327,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -351,7 +351,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, bool, read_write> = var
 }
 
@@ -374,7 +374,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -398,7 +398,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, bool, read_write> = var
 }
 
@@ -421,7 +421,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -445,7 +445,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -469,7 +469,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():bool {
   $B1: {
     ret true
   }
@@ -506,7 +506,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():bool {
   $B1: {
     ret true
   }
@@ -542,7 +542,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -566,7 +566,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -590,7 +590,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -614,7 +614,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -638,7 +638,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -662,7 +662,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -686,7 +686,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -710,7 +710,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -733,7 +733,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 0u
   }
@@ -757,7 +757,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, u32, read_write> = var
 }
 
@@ -782,7 +782,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():f32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():f32 {
   $B1: {
     ret 0.0f
   }
@@ -820,7 +820,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func(%p:bool):bool {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func(%p:bool):bool {
   $B1: {
     ret true
   }
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/builtin_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/builtin_test.cc
index 7423f12..ab4b650 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/builtin_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/builtin_test.cc
@@ -46,7 +46,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %i:ptr<private, f32, read_write> = var, 1.0f
 }
 
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/call_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/call_test.cc
index eb3dac7..f8342c8 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/call_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/call_test.cc
@@ -48,7 +48,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():f32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():f32 {
   $B1: {
     ret 0.0f
   }
@@ -74,7 +74,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test_function = @fragment func():void {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test_function = @fragment func():void {
   $B1: {
     discard
     ret
@@ -91,7 +91,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func(%p:f32):void {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func(%p:f32):void {
   $B1: {
     ret
   }
@@ -113,7 +113,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %i:ptr<private, i32, read_write> = var, 1i
 }
 
@@ -135,7 +135,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %i:ptr<private, vec3<f32>, read_write> = var, vec3<f32>(0.0f)
 }
 
@@ -150,7 +150,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %i:ptr<private, f32, read_write> = var, 1.0f
 }
 
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/function_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/function_test.cc
index 1af67b1..2ace620e 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/function_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/function_test.cc
@@ -47,7 +47,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = @vertex func():vec4<f32> [@position] {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test = @vertex func():vec4<f32> [@position] {
   $B1: {
     ret vec4<f32>(0.0f)
   }
@@ -62,7 +62,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = @fragment func():void {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test = @fragment func():void {
   $B1: {
     ret
   }
@@ -77,7 +77,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test = @compute @workgroup_size(8, 4, 2) func():void {
   $B1: {
     ret
@@ -93,7 +93,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():vec3<f32> {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test = func():vec3<f32> {
   $B1: {
     ret vec3<f32>(0.0f)
   }
@@ -108,7 +108,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():f32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test = func():f32 {
   $B1: {
     if true [t: $B2, f: $B3] {  # if_1
       $B2: {  # true
@@ -132,7 +132,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = @vertex func():vec4<f32> [@position] {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test = @vertex func():vec4<f32> [@position] {
   $B1: {
     ret vec4<f32>(1.0f, 2.0f, 3.0f, 4.0f)
   }
@@ -148,7 +148,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test = @vertex func():vec4<f32> [@invariant, @position] {
   $B1: {
     ret vec4<f32>(1.0f, 2.0f, 3.0f, 4.0f)
@@ -164,7 +164,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test = @fragment func():vec4<f32> [@location(1)] {
   $B1: {
     ret vec4<f32>(1.0f, 2.0f, 3.0f, 4.0f)
@@ -182,7 +182,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test = @fragment func():vec4<f32> [@location(1), @interpolate(linear, centroid)] {
   $B1: {
     ret vec4<f32>(1.0f, 2.0f, 3.0f, 4.0f)
@@ -199,7 +199,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = @fragment func():f32 [@frag_depth] {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test = @fragment func():f32 [@frag_depth] {
   $B1: {
     ret 1.0f
   }
@@ -215,7 +215,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = @fragment func():u32 [@sample_mask] {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test = @fragment func():u32 [@sample_mask] {
   $B1: {
     ret 1u
   }
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/let_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/let_test.cc
index 8b67280..761e584 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/let_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/let_test.cc
@@ -44,7 +44,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:i32 = let 42i
@@ -60,7 +60,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:i32 = let 3i
@@ -78,7 +78,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:i32 = let 1i
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/materialize_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/materialize_test.cc
index 7b1b1e6..f09beb8 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/materialize_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/materialize_test.cc
@@ -46,7 +46,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test_function = func():f32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%test_function = func():f32 {
   $B1: {
     ret 2.0f
   }
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/program_to_ir_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/program_to_ir_test.cc
index 466498e..3e8e597 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/program_to_ir_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/program_to_ir_test.cc
@@ -83,7 +83,7 @@
 
     EXPECT_EQ(m->functions[0]->Stage(), core::ir::Function::PipelineStage::kUndefined);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():void {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():void {
   $B1: {
     ret
   }
@@ -104,7 +104,7 @@
 
     EXPECT_EQ(m->functions[0]->Stage(), core::ir::Function::PipelineStage::kUndefined);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func(%a:u32):u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func(%a:u32):u32 {
   $B1: {
     ret %a
   }
@@ -126,7 +126,7 @@
 
     EXPECT_EQ(m->functions[0]->Stage(), core::ir::Function::PipelineStage::kUndefined);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func(%a:u32, %b:i32, %c:bool):void {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func(%a:u32, %b:i32, %c:bool):void {
   $B1: {
     ret
   }
@@ -154,7 +154,7 @@
 
     ASSERT_EQ(1u, m.functions.Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     if true [t: $B2, f: $B3] {  # if_1
@@ -182,7 +182,7 @@
 
     ASSERT_EQ(1u, m.functions.Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     if true [t: $B2] {  # if_1
@@ -207,7 +207,7 @@
 
     ASSERT_EQ(1u, m.functions.Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     if true [t: $B2, f: $B3] {  # if_1
@@ -235,7 +235,7 @@
 
     ASSERT_EQ(1u, m.functions.Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     if true [t: $B2, f: $B3] {  # if_1
@@ -262,7 +262,7 @@
 
     auto m = res.Move();
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     if true [t: $B2] {  # if_1
@@ -296,7 +296,7 @@
     EXPECT_EQ(0u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(0u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2] {  # loop_1
@@ -326,7 +326,7 @@
     EXPECT_EQ(1u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(1u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2, c: $B3] {  # loop_1
@@ -364,7 +364,7 @@
     EXPECT_EQ(1u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(1u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2, c: $B3] {  # loop_1
@@ -391,7 +391,7 @@
     ASSERT_EQ(res, Success);
 
     auto m = res.Move();
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2, c: $B3] {  # loop_1
@@ -425,7 +425,7 @@
     EXPECT_EQ(1u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(1u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2, c: $B3] {  # loop_1
@@ -462,7 +462,7 @@
     EXPECT_EQ(0u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(0u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2] {  # loop_1
@@ -500,7 +500,7 @@
     EXPECT_EQ(0u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(0u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2] {  # loop_1
@@ -535,7 +535,7 @@
     EXPECT_EQ(0u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(0u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2] {  # loop_1
@@ -574,7 +574,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2, c: $B3] {  # loop_1
@@ -642,7 +642,7 @@
     EXPECT_EQ(1u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(1u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2, c: $B3] {  # loop_1
@@ -682,7 +682,7 @@
     EXPECT_EQ(1u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(0u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2, c: $B3] {  # loop_1
@@ -722,7 +722,7 @@
     EXPECT_EQ(2u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(1u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [i: $B2, b: $B3, c: $B4] {  # loop_1
@@ -771,7 +771,7 @@
     EXPECT_EQ(1u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(0u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [i: $B2, b: $B3] {  # loop_1
@@ -804,7 +804,7 @@
     EXPECT_EQ(0u, loop->Body()->InboundSiblingBranches().Length());
     EXPECT_EQ(0u, loop->Continuing()->InboundSiblingBranches().Length());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     loop [b: $B2] {  # loop_1
@@ -849,7 +849,7 @@
     ASSERT_EQ(1u, cases[2].selectors.Length());
     EXPECT_TRUE(cases[2].selectors[0].IsDefault());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     switch 1i [c: (0i, $B2), c: (1i, $B3), c: (default, $B4)] {  # switch_1
@@ -897,7 +897,7 @@
 
     EXPECT_TRUE(cases[0].selectors[2].IsDefault());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     switch 1i [c: (0i 1i default, $B2)] {  # switch_1
@@ -928,7 +928,7 @@
     ASSERT_EQ(1u, cases[0].selectors.Length());
     EXPECT_TRUE(cases[0].selectors[0].IsDefault());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     switch 1i [c: (default, $B2)] {  # switch_1
@@ -968,7 +968,7 @@
 
     // This is 1 because the if is dead-code eliminated and the return doesn't happen.
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     switch 1i [c: (0i, $B2), c: (default, $B3)] {  # switch_1
@@ -1010,7 +1010,7 @@
     ASSERT_EQ(1u, cases[1].selectors.Length());
     EXPECT_TRUE(cases[1].selectors[0].IsDefault());
 
-    EXPECT_EQ(Disassemble(m),
+    EXPECT_EQ(Disassemble(m).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     switch 1i [c: (0i, $B2), c: (default, $B3)] {  # switch_1
@@ -1034,7 +1034,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%b = func():i32 {
   $B1: {
     ret 1i
@@ -1059,7 +1059,7 @@
     ASSERT_EQ(m, Success);
 
     EXPECT_EQ(
-        Disassemble(m.Get()),
+        Disassemble(m.Get()).Plain(),
         R"(%f = @fragment func(%a:vec4<f32> [@invariant, @position]):vec4<f32> [@location(1)] {
   $B1: {
     ret %a
@@ -1075,7 +1075,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%f = @fragment func(%a:f32 [@location(2)]):f32 [@location(1)] {
   $B1: {
     ret %a
@@ -1096,7 +1096,7 @@
     ASSERT_EQ(m, Success);
 
     EXPECT_EQ(
-        Disassemble(m.Get()),
+        Disassemble(m.Get()).Plain(),
         R"(%f = @fragment func(%a:f32 [@location(2), @interpolate(linear, centroid)]):f32 [@location(1)] {
   $B1: {
     ret %a
@@ -1115,7 +1115,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%f = @fragment func(%a:f32 [@location(2), @interpolate(flat)]):f32 [@location(1)] {
   $B1: {
     ret %a
@@ -1138,7 +1138,7 @@
 
     EXPECT_EQ(m->functions[0]->Stage(), core::ir::Function::PipelineStage::kUndefined);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():void {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():void {
   $B1: {
     ret
   }
@@ -1159,7 +1159,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%f = func():void {
   $B1: {
     ret
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/shadowing_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/shadowing_test.cc
index c3251f5..6803cd6 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/shadowing_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/shadowing_test.cc
@@ -59,7 +59,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(S = struct @align(4) {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(S = struct @align(4) {
   i:i32 @offset(0)
 }
 
@@ -87,7 +87,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(S = struct @align(4) {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(S = struct @align(4) {
   i:i32 @offset(0)
 }
 
@@ -113,7 +113,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %i:ptr<private, i32, read_write> = var, 1i
 }
 
@@ -145,7 +145,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %i:ptr<private, i32, read_write> = var, 1i
 }
 
@@ -178,7 +178,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     if true [t: $B2] {  # if_1
@@ -217,7 +217,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     if true [t: $B2] {  # if_1
@@ -252,7 +252,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [b: $B2, c: $B3] {  # loop_1
@@ -298,7 +298,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [b: $B2, c: $B3] {  # loop_1
@@ -342,7 +342,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [i: $B2, b: $B3] {  # loop_1
@@ -386,7 +386,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [i: $B2, b: $B3] {  # loop_1
@@ -429,7 +429,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [i: $B2, b: $B3] {  # loop_1
@@ -476,7 +476,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [i: $B2, b: $B3] {  # loop_1
@@ -527,7 +527,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [b: $B2, c: $B3] {  # loop_1
@@ -581,7 +581,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [b: $B2, c: $B3] {  # loop_1
@@ -635,7 +635,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [b: $B2, c: $B3] {  # loop_1
@@ -685,7 +685,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     loop [b: $B2, c: $B3] {  # loop_1
@@ -735,7 +735,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     %3:i32 = load %i
@@ -783,7 +783,7 @@
 
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%f = func():i32 {
   $B1: {
     %i:ptr<function, i32, read_write> = var
     %3:i32 = load %i
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/store_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/store_test.cc
index b2ac91e..b8c04a3 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/store_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/store_test.cc
@@ -47,7 +47,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %a:ptr<private, u32, read_write> = var
 }
 
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/unary_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/unary_test.cc
index 8342e48..dbf7b24 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/unary_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/unary_test.cc
@@ -46,7 +46,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():bool {
   $B1: {
     ret false
   }
@@ -70,7 +70,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():vec4<bool> {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():vec4<bool> {
   $B1: {
     ret vec4<bool>(false)
   }
@@ -94,7 +94,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():u32 {
   $B1: {
     ret 1u
   }
@@ -118,7 +118,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():i32 {
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"(%my_func = func():i32 {
   $B1: {
     ret 1i
   }
@@ -143,7 +143,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, i32, read_write> = var
 }
 
@@ -167,7 +167,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %v1:ptr<private, i32, read_write> = var
 }
 
diff --git a/src/tint/lang/wgsl/reader/program_to_ir/var_test.cc b/src/tint/lang/wgsl/reader/program_to_ir/var_test.cc
index c683285..16cf0c9 100644
--- a/src/tint/lang/wgsl/reader/program_to_ir/var_test.cc
+++ b/src/tint/lang/wgsl/reader/program_to_ir/var_test.cc
@@ -45,7 +45,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %a:ptr<private, u32, read_write> = var
 }
 
@@ -59,7 +59,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %a:ptr<private, u32, read_write> = var, 2u
 }
 
@@ -72,7 +72,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"($B1: {  # root
+    EXPECT_EQ(Disassemble(m.Get()).Plain(), R"($B1: {  # root
   %a:ptr<storage, u32, read> = var @binding_point(2, 3)
 }
 
@@ -86,7 +86,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, u32, read_write> = var
@@ -104,7 +104,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, u32, read_write> = var, 2u
@@ -122,7 +122,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, u32, read_write> = var
@@ -142,7 +142,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, i32, read_write> = var
@@ -179,7 +179,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%f = func(%p:i32):i32 {
   $B1: {
     ret %p
@@ -225,7 +225,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%f = func(%p:i32):i32 {
   $B1: {
     ret %p
@@ -273,7 +273,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%f = func(%p:i32):i32 {
   $B1: {
     ret %p
@@ -305,7 +305,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%test_function = @compute @workgroup_size(1, 1, 1) func():void {
   $B1: {
     %a:ptr<function, i32, read_write> = var
@@ -344,7 +344,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%f = func(%p:i32):i32 {
   $B1: {
     ret %p
@@ -396,7 +396,7 @@
     auto m = Build();
     ASSERT_EQ(m, Success);
 
-    EXPECT_EQ(Disassemble(m.Get()),
+    EXPECT_EQ(Disassemble(m.Get()).Plain(),
               R"(%f = func(%p:i32):i32 {
   $B1: {
     ret %p
diff --git a/src/tint/lang/wgsl/writer/ir_to_program/ir_to_program_test.cc b/src/tint/lang/wgsl/writer/ir_to_program/ir_to_program_test.cc
index 30e6795..68d4db1 100644
--- a/src/tint/lang/wgsl/writer/ir_to_program/ir_to_program_test.cc
+++ b/src/tint/lang/wgsl/writer/ir_to_program/ir_to_program_test.cc
@@ -51,7 +51,7 @@
 IRToProgramTest::Result IRToProgramTest::Run() {
     Result result;
 
-    result.ir = tint::core::ir::Disassemble(mod);
+    result.ir = tint::core::ir::Disassemble(mod).Plain();
 
     ProgramOptions options;
     options.allowed_features = AllowedFeatures::Everything();
diff --git a/src/tint/lang/wgsl/writer/raise/ptr_to_ref_test.cc b/src/tint/lang/wgsl/writer/raise/ptr_to_ref_test.cc
index b663af0..3862749 100644
--- a/src/tint/lang/wgsl/writer/raise/ptr_to_ref_test.cc
+++ b/src/tint/lang/wgsl/writer/raise/ptr_to_ref_test.cc
@@ -67,7 +67,7 @@
     /// @returns the transformed module as a disassembled string
     std::string str() {
         core::ir::Disassembler dis(mod);
-        return "\n" + dis.Disassemble();
+        return "\n" + dis.Disassemble().Plain();
     }
 
   protected:
diff --git a/src/tint/lang/wgsl/writer/raise/rename_conflicts_test.cc b/src/tint/lang/wgsl/writer/raise/rename_conflicts_test.cc
index 1c805b1..7be25fc 100644
--- a/src/tint/lang/wgsl/writer/raise/rename_conflicts_test.cc
+++ b/src/tint/lang/wgsl/writer/raise/rename_conflicts_test.cc
@@ -67,7 +67,7 @@
     /// @returns the transformed module as a disassembled string
     std::string str() {
         core::ir::Disassembler dis(mod);
-        return "\n" + dis.Disassemble();
+        return "\n" + dis.Disassemble().Plain();
     }
 
   protected:
diff --git a/src/tint/lang/wgsl/writer/writer_test.cc b/src/tint/lang/wgsl/writer/writer_test.cc
index d01d1df..ca2f339 100644
--- a/src/tint/lang/wgsl/writer/writer_test.cc
+++ b/src/tint/lang/wgsl/writer/writer_test.cc
@@ -65,14 +65,14 @@
     Result Run(std::string_view expected_wgsl) {
         Result result;
 
-        result.ir_pre_raise = core::ir::Disassemble(mod);
+        result.ir_pre_raise = core::ir::Disassemble(mod).Plain();
 
         if (auto res = tint::wgsl::writer::Raise(mod); res != Success) {
             result.err = res.Failure().reason.Str();
             return result;
         }
 
-        result.ir_post_raise = core::ir::Disassemble(mod);
+        result.ir_post_raise = core::ir::Disassemble(mod).Plain();
 
         writer::ProgramOptions program_options;
         program_options.allowed_features = AllowedFeatures::Everything();
diff --git a/src/tint/utils/text/string_stream.h b/src/tint/utils/text/string_stream.h
index ab96301..45aaaab 100644
--- a/src/tint/utils/text/string_stream.h
+++ b/src/tint/utils/text/string_stream.h
@@ -197,8 +197,8 @@
         return *this;
     }
 
-    /// @returns the current location in the output stream
-    uint32_t tellp() { return static_cast<uint32_t>(sstream_.tellp()); }
+    /// @returns the number of UTF-8 code units (bytes) have been written to the string.
+    size_t Length() { return static_cast<size_t>(sstream_.tellp()); }
 
     /// @returns the string contents of the stream
     std::string str() const { return sstream_.str(); }
diff --git a/src/tint/utils/text/styled_text.h b/src/tint/utils/text/styled_text.h
index 21a82aa..556099b 100644
--- a/src/tint/utils/text/styled_text.h
+++ b/src/tint/utils/text/styled_text.h
@@ -117,9 +117,9 @@
                        value.values);
             *this << old_style;
         } else {
-            uint32_t offset = stream_.tellp();
+            size_t offset = stream_.Length();
             stream_ << value;
-            spans_.Back().length += stream_.tellp() - offset;
+            spans_.Back().length += stream_.Length() - offset;
         }
         return *this;
     }
@@ -136,6 +136,9 @@
         }
     }
 
+    /// @returns the number of UTF-8 code units (bytes) have been written to the string.
+    size_t Length() { return stream_.Length(); }
+
   private:
     struct Span {
         TextStyle style;