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Created October 3, 2025 07:12
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Some quick notes copied out of a ChatGPT convo + some manual sources that I used recently when trying to gather appropriate resources to report a Google Chrome (aka: Chromium) performance issue / memory leak.
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reporting-chrome-performance-issues.md

Reporting Chrome Performance Issues

Some quick notes copied out of a ChatGPT convo + some manual sources that I used recently when trying to gather appropriate resources to report a Google Chrome (aka: Chromium) performance issue / memory leak.

Table of Contents

Main Links

The following are probably your main canonical sources:

Though these may also be relevant/useful:

Random Unsorted Notes

The following are some random unsorted notes, mostly (if not entirely) copied out of a ChatGPT (GPT-5) conversation; and which may not have been fully reviewed/verified, so take it with a grain of salt.

Original Prompt:

My core chrome browser is seemingly using a lot of RAM and CPU in a way that the internal task manager doesn't correlate it with any open tabs/etc. How can I best report this to the Chrome team, and capture any relevant diagnostics/etc?

Assorted snippets from that chat:

  • System-level process dump / profiling
    • e.g. full process memory / CPU stack traces to see which threads or modules are burning CPU
    • Use OS tools (e.g. Windows: Process Explorer / WPR / xperf; macOS: Instruments / sample; Linux: pprof / perf)
  • Chrome’s internal “about” / diagnostic pages
    • e.g. chrome://memory-redirect, chrome://histograms, chrome://tracing, chrome://net-internals etc.
    • These pages sometimes reveal resource sinks or internal metrics
  • Screenshots + system metrics
    • e.g. Task Manager / Activity Monitor showing CPU/RAM usage over time
    • Helps correlate your high usage to what you saw
  • Gather OS-level profiling data
    • On Windows: use tools like Process Explorer, Performance Monitor, or Windows Performance Recorder to sample CPU usage, stack traces, module loads, etc.
    • On macOS: use Instruments, “sample process,” or Activity Monitor’s Sample Process
    • On Linux: perf, top, htop, gdb/pmap, or strace / ltrace / eBPF tools
  • Collect memory dumps if needed
    • In extreme cases, a memory dump / heap snapshot may help—but this is more advanced and usually only needed if you suspect memory leaks in Chrome.
  • Prepare your bug report
    • In your bug report to Chrome / Chromium, include:
    • Short but precise summary of the symptom (e.g. “Chrome becomes unresponsive and holds 80% CPU, but Chrome Task Manager shows no single tab/extension using >5 %”)
    • Steps to reproduce
    • Chrome version + build number
    • OS version, hardware specs
    • The collected logs (chrome_debug.log, NetLog, profiling samples)
    • Screenshots / screen recordings / system metric graphs
    • Any workarounds or observations (does restarting fix it? Does disabling one extension help? etc.)

How to actually report to the Chrome / Chromium team:

Once you have your diagnostics:

  • Use Chrome’s built-in “Report an issue” feature: Menu → Help → Report an issue. You can attach logs, screenshots, steps to reproduce, etc. Google Help
  • If the built-in reporter is insufficient (e.g. for raw logs, NetLog, or deep debugging), you can file a bug in the Chromium issue tracker: https://bugs.chromium.org
    • Choose appropriate component (e.g. Performance, Memory, Browser, Network)
    • Mark it “Restricted” if you need it visible only to Google engineers (since public bugs may leak private info) chromium.org
    • Attach your logs, explain everything as above
  • In your bug text, you can ask for the bug visibility to be restricted before attaching logs if you’re concerned about privacy. chromium.org

Chrome-internal tools you can use live:

  • Chrome Task Manager (Shift+Esc)
    • You’ve already checked this — it sometimes won’t show the hidden culprit, but still worth capturing a screenshot when the problem is happening.
  • chrome://memory-internals
    • Shows live memory allocation breakdowns per process.
  • chrome://tracing
    • You can record a performance trace without restarting Chrome:
      • Open chrome://tracing
      • Click “Record” → choose categories (start with “memory”, “blink”, “v8”, “cc”, “toplevel”)
      • Let it run for 10–30 seconds while CPU/RAM are high
      • Stop recording → save trace file (.json.gz)
      • This captures what the threads were doing.
  • chrome://net-export
    • Lets you capture networking activity in the current session. Click “Start Logging to Disk”, reproduce for a bit, then “Stop Logging” → download .json. This helps if runaway requests are chewing resources.
  • chrome://histograms
    • Dumps all Chrome UMA histograms — not always human-friendly, but can give developers a view of subsystem state.
  • chrome://system
    • General system/Chrome info, including command line, feature flags, GPU state, extensions, etc.

OS-level tools while Chrome is running:

  • macOS
    • Use Activity Monitor, select the main Google Chrome process, and do Sample Process for ~30s. This creates a stack trace snapshot.
    • top -o cpu or ps -M <pid> in Terminal shows thread usage.
  • Windows
    • Task Manager → Details → Right-click chrome.exe → Create Dump File
    • Or use Sysinternals Process Explorer → double-click Chrome process → “Threads” tab, see which functions are hot.
  • Linux
    • top or htop → identify high-CPU chrome process by PID
    • pstack <pid> or perf top -p <pid> to see where CPU cycles are going
    • pmap <pid> to see memory allocations.

Even one process sample/dump at the time of the spike is very valuable.

When you file your Chrome bug (via “Report an issue” or bugs.chromium.org:

  • Describe: “Chrome main process consuming X% CPU and Y GB RAM. Chrome Task Manager shows low usage across tabs/extensions.”
  • Attach:
    • Trace from chrome://tracing
    • NetLog from chrome://net-export (if relevant)
    • Screenshots of chrome://memory-internals and OS Task Manager
    • System sample/dump (if comfortable sharing — these can contain private data, so scrub before uploading or request restricted visibility).

Example Submissions

This is the bug report I submitted about the performance issues I was having when I first created these notes:

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