Mozilla Automation TeamcanovaSep 3, 20261 min readrelease notesintermediate

Firefox Profiler Deployment (September 3, 2026)

Summary

Firefox Profiler 0.9.0 release with a handful of CLI improvements (unlimited limit flag, better marker handling, network request count), UI tweaks (dark‑mode contrast, publish panel component), and library updates (oxfmt, typed arrays). Localisation added for several languages.

CLI now accepts `--limit 0` for unlimited results and prints a loud truncation warning.
CLI avoids stack overflow on large marker threads and reports a single time base for text/JSON output.
Network request prefetch visibility added to the UI.
FrameTable gains a lib column and more typed‑array columns for performance.

These changes tighten the profiling tool’s usability for large‑scale data sets and improve UI consistency across themes, which matters for developers diagnosing performance regressions in Firefox.

3/10

cli performance profiling devtools release

Related reading

Firefox Profiler Deployment (August 10, 2026)mozilla.org
Firefox Profiler 0.8.0 is now live, adding CLI source‑map support, a new Network track, and several internal optimizations. The release also improves error handling, marker handling, and updates localizations.
Mozilla Automation Teammozilla.orgcanova1mo1 minrelease
Firefox new release cadence and what to expect mozilla.org
Firefox is shifting to a two‑week release cadence starting with version 155 on Sep 1 2026 to deliver bug fixes faster and make schedules predictable; SUMO contributors will see more frequent support spikes and must adapt content and localization workflows.
Mozilla Automation Teammozilla.orgRizki Kelimutu1mo4 min
Firefox DevTools MCP 0.10.3 released mozilla.org
Firefox DevTools MCP 0.10.3 is released, introducing a new `close_firefox_session` tool, full-page screenshot capability, and configurable download folders. This update also includes bug fixes and clarifies the usage of `restart_firefox` for controlling Firefox via WebDriver BiDi.
Mozilla Automation Teammozilla.orgjdescottes4d1 minrelease
PerfCompare just deployed (Sept 3, 2026)mozilla.org
Mozilla released a new PerfCompare version featuring a Simple View UI with checkbox column selection, expanded rows, and several bug fixes, including filter URL handling and NaN errors in stats.
Mozilla Automation Teammozilla.orgcsevere18d1 minrelease
The Road to Better Performance Profiles – Part 2 mozilla.org
Mozilla’s Automation Team added native system‑wide profiling to their CI pipelines for Speedometer 3 on Windows, macOS, Linux, and Android, using xperf, perf, and simpleperf together with the samply toolchain, and modernized the mozgeckoprofiler symbolication stack by replacing the legacy Eliot service with samply and profiler‑edit.
Mozilla Automation Teammozilla.orgAbhishek Nimalan26d5 min
High-speed Release Trains – These Weeks in Firefox: Issue 209 mozilla.org
Firefox 155 shipped via a new 2‑week release train; the week’s highlights include a WebExtensions theme API addition, multi‑context address bar in Nightly, DevTools stylesheet editing in the JS debugger, and extensive New Tab page UI/telemetry work (stocks widget, privacy widget, policy‑locked settings). The post also calls out many volunteer contributors and a handful of infrastructure tweaks (T…
Mozilla Automation Teammozilla.orgKatherine Patenio4d9 min

Firefox Profiler Deployment (September 3, 2026)

Summary

Related reading

Firefox Profiler Deployment (August 10, 2026)mozilla.org

Firefox new release cadence and what to expectmozilla.org

Firefox DevTools MCP 0.10.3 releasedmozilla.org

PerfCompare just deployed (Sept 3, 2026)mozilla.org

The Road to Better Performance Profiles – Part 2mozilla.org

High-speed Release Trains – These Weeks in Firefox: Issue 209mozilla.org

Firefox new release cadence and what to expect mozilla.org

Firefox DevTools MCP 0.10.3 released mozilla.org

The Road to Better Performance Profiles – Part 2 mozilla.org

High-speed Release Trains – These Weeks in Firefox: Issue 209 mozilla.org