diff --git a/BUILD.gn b/BUILD.gn
index e03aa8d..de8f258 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1020,7 +1020,6 @@
     ":dawn_utils",
     ":libdawn_native",
     ":libdawn_wire",
-    "${dawn_jsoncpp_dir}:jsoncpp",
     "${dawn_root}/src/common",
     "${dawn_root}/src/dawn:dawncpp",
     "${dawn_root}/src/dawn:libdawn_proc",
diff --git a/DEPS b/DEPS
index c5913f9..1bc6730 100644
--- a/DEPS
+++ b/DEPS
@@ -73,17 +73,6 @@
     'condition': 'dawn_standalone',
   },
 
-  # jsoncpp for perf tests trace events
-  'third_party/jsoncpp': {
-    'url': '{chromium_git}/chromium/src/third_party/jsoncpp@571788934b5ee8643d53e5d054534abbe6006168',
-    'condition': 'dawn_standalone',
-  },
-
-  'third_party/jsoncpp/source': {
-    'url' : '{chromium_git}/external/github.com/open-source-parsers/jsoncpp@645250b6690785be60ab6780ce4b58698d884d11',
-    'condition': 'dawn_standalone',
-  },
-
   # GLFW for tests and samples
   'third_party/glfw': {
     'url': '{chromium_git}/external/github.com/glfw/glfw@2de2589f910b1a85905f425be4d32f33cec092df',
diff --git a/build_overrides/dawn.gni b/build_overrides/dawn.gni
index 0d44f3b..0378ec1 100644
--- a/build_overrides/dawn.gni
+++ b/build_overrides/dawn.gni
@@ -27,7 +27,6 @@
 dawn_jinja2_dir = "//third_party/jinja2"
 dawn_glfw_dir = "//third_party/glfw"
 dawn_googletest_dir = "//third_party/googletest"
-dawn_jsoncpp_dir = "//third_party/jsoncpp"
 dawn_shaderc_dir = "//third_party/shaderc"
 dawn_spirv_tools_dir = "//third_party/SPIRV-Tools"
 dawn_spirv_cross_dir = "//third_party/spirv-cross"
diff --git a/scripts/dawn_overrides_with_defaults.gni b/scripts/dawn_overrides_with_defaults.gni
index b7eaee1..0886e03 100644
--- a/scripts/dawn_overrides_with_defaults.gni
+++ b/scripts/dawn_overrides_with_defaults.gni
@@ -41,10 +41,6 @@
   dawn_googletest_dir = "//third_party/googletest"
 }
 
-if (!defined(dawn_jsoncpp_dir)) {
-  dawn_jsoncpp_dir = "//third_party/jsoncpp"
-}
-
 if (!defined(dawn_shaderc_dir)) {
   dawn_shaderc_dir = "//third_party/shaderc"
 }
diff --git a/src/tests/perf_tests/DawnPerfTest.cpp b/src/tests/perf_tests/DawnPerfTest.cpp
index 3bd641b..64b4d70 100644
--- a/src/tests/perf_tests/DawnPerfTest.cpp
+++ b/src/tests/perf_tests/DawnPerfTest.cpp
@@ -20,9 +20,6 @@
 #include "tests/perf_tests/DawnPerfTestPlatform.h"
 #include "utils/Timer.h"
 
-#include <json/value.h>
-#include <json/writer.h>
-
 #include <fstream>
 #include <limits>
 
@@ -36,45 +33,37 @@
         std::ofstream outFile;
         outFile.open(traceFile, std::ios_base::app);
 
-        Json::StreamWriterBuilder builder;
-        std::unique_ptr<Json::StreamWriter> writer(builder.newStreamWriter());
-
         for (const DawnPerfTestPlatform::TraceEvent& traceEvent : traceEventBuffer) {
-            Json::Value value(Json::objectValue);
-
-            const Json::LargestInt microseconds =
-                static_cast<Json::LargestInt>(traceEvent.timestamp * 1000.0 * 1000.0);
-
-            char phase[2] = {traceEvent.phase, '\0'};
-
-            value["name"] = traceEvent.name;
+            const char* category = nullptr;
             switch (traceEvent.category) {
                 case dawn_platform::TraceCategory::General:
-                    value["cat"] = "general";
+                    category = "general";
                     break;
                 case dawn_platform::TraceCategory::Validation:
-                    value["cat"] = "validation";
+                    category = "validation";
                     break;
                 case dawn_platform::TraceCategory::Recording:
-                    value["cat"] = "recording";
+                    category = "recording";
                     break;
                 case dawn_platform::TraceCategory::GPUWork:
-                    value["cat"] = "gpu";
+                    category = "gpu";
                     break;
                 default:
                     UNREACHABLE();
             }
-            value["ph"] = &phase[0];
-            value["id"] = traceEvent.id;
-            value["tid"] = traceEvent.threadId;
-            value["ts"] = microseconds;
-            value["pid"] = "Dawn";
 
-            outFile << ", ";
-            writer->write(value, &outFile);
-            outFile.flush();
+            uint64_t microseconds = static_cast<uint64_t>(traceEvent.timestamp * 1000.0 * 1000.0);
+
+            outFile << ", { "
+                    << "\"name\": \"" << traceEvent.name << "\", "
+                    << "\"cat\": \"" << category << "\", "
+                    << "\"ph\": \"" << traceEvent.phase << "\", "
+                    << "\"id\": " << traceEvent.id << ", "
+                    << "\"tid\": " << traceEvent.threadId << ", "
+                    << "\"ts\": " << microseconds << ", "
+                    << "\"pid\": \"Dawn\""
+                    << " }";
         }
-
         outFile.close();
     }
 
@@ -115,7 +104,7 @@
         if (strcmp("-h", argv[i]) == 0 || strcmp("--help", argv[i]) == 0) {
             dawn::InfoLog()
                 << "Additional flags:"
-                << " [--calibration] [--override-steps=x] [--enable-tracing] [--trace-file=file]\n"
+                << " [--calibration] [--override-steps=x] [--trace-file=file]\n"
                 << "  --calibration: Only run calibration. Calibration allows the perf test"
                    " runner script to save some time.\n"
                 << " --override-steps: Set a fixed number of steps to run for each test\n"