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New Features in Mach Try Perf

Gregory Mierzwinski
October 26, 2023

Since we’ve added mach try perf, quite a few improvements have been made, along with new features added. Below, you’ll find a summary of the most important changes. If mach … Read more

Side-by-side of an improvement that should be a regression

Ancient Bug Discovered in the Visual Metrics Processing Script

Gregory Mierzwinski
March 3, 2023

Recently, we had an odd regression in our page load tests. You can find that bug here. The regression was quite large, but when a developer investigated, they found that … Read more

Mach Try Perf Demo

Improving the Test Selection Experience with Mach Try Perf

Gregory Mierzwinski
February 28, 2023

If you’ve ever tried to figure out what performance tests you should run to target some component, and got lost in the nomenclature of our CI task names, then you’re … Read more

Nazım Can Altınova talks about the new things in Firefox PRofiler.

The Firefox Profiler team was at FOSDEM 2023

Julien Wajsberg
February 27, 2023

The Free and Open source Software Developers’ European Meeting (FOSDEM) 2023 took place on the 4th and 5th of February. This was the first in-person FOSDEM since 2020, and for … Read more

Automatically generated side-by-side video

Announcing side-by-side videos for performance regressions

Alexandru Ionescu
February 22, 2023

Early in the fall, I was talking about integrating the side-by-side tool in Continuous Integration (CI). This started as a script for generating a side-by-side comparison between two page load … Read more

Screenshot of the performance impact calculator

Understanding Performance Impact

Dave Hunt
November 7, 2022

A few years ago, a small group of engineers at Mozilla introduced a process to identify the tasks that would have the greatest impact on the performance of Firefox. They … Read more

What’s new with the Firefox Profiler? (Q3 2022)

Julien Wajsberg
October 27, 2022

As the Perf-Tools team, we are responsible for the Firefox Profiler. This newsletter gives an overview of the new features and improvements we’ve made in the third quarter of 2022. … Read more

A different perspective

Alexandru Ionescu
September 15, 2022

Usually, in our articles, we talk about performance from the performance engineer’s perspective, but in this one, I want to take a step back and look at it from another … Read more

Collage of images from the 2022 H1 blog post

Performance Tools Newsletter (H1 2022)

Gerald Squelart
July 29, 2022

As the Perf-Tools team, we are responsible for the Firefox Profiler. This newsletter gives an overview of the new features and improvements we’ve done in the first half of 2022. … Read more

Tumblr pageload

Migrating to Browsertime for Performance Testing

Gregory Mierzwinski
July 11, 2022

Originally, we used a Web Extension for doing performance testing on Firefox in our Raptor test harness. But, we needed to add new features such as visual metrics, so in … Read more

Reworking our Visual Metrics Processing System

Gregory Mierzwinski
July 11, 2022

Our visual metrics processing system used to use two separate machines to produce visual metrics from our pageload tests. In this post, I’ll describe how we moved to a single-machine … Read more

PerfCompare performance comparison tool

Introducing A New Performance Comparison Tool – PerfCompare

Kimberly Sereduck
June 30, 2022

Introduction I have been a member of the performance test team for the past two and a half years. During that time, the performance team has had many discussions about … Read more

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  • Performance Tools Newsletter (H1 Edition)
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  • Introducing the Chrome Extension for the Firefox Profiler

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    More articles

    • Sheriffing
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    Sheriffing

    • Performance Sheriff Newsletter (March 2022)
      April 7, 2022
    • Performance Sheriff Newsletter (February 2022)
      March 17, 2022
    • Performance Sheriff Newsletter (January 2022)
      March 16, 2022
    • Performance Sheriff Newsletter (December 2021)
      January 21, 2022
    • Performance Sheriff Newsletter (November 2021)
      December 21, 2021

    Testing

    • The Road to Better Performance Profiles
      February 3, 2026
    • Announcing PerfCompare: the new comparison tool !
      October 16, 2024
    • Upgrading Page Load Tests to Mitmproxy 7
      November 19, 2021
    • What’s new in Perfherder?
      July 15, 2021
    • Using the Mach Perftest Notebook
      November 12, 2020

    Profiling

    • The Road to Better Performance Profiles
      February 3, 2026
    • Introducing the Chrome Extension for the Firefox Profiler
      December 12, 2024
    • Performance Tools Newsletter (H1 2022)
      July 29, 2022
    • Performance Tools Newsletter (Q3 2021)
      November 15, 2021
    • Performance Tools Newsletter (H1 2021)
      July 8, 2021

    Highlights

    • Firefox 144 ships interactionId for INP
      October 15, 2025
    • Performance Tools Newsletter (H1 Edition)
      July 18, 2025
    • Performance Testing Newsletter (Q4 Edition)
      January 31, 2025
    • Performance Testing Newsletter (Q3 Edition)
      October 31, 2024
    • Performance Testing Newsletter, Q2 Edition
      August 8, 2024

    Uncategorized

    • Introducing the Chrome Extension for the Firefox Profiler
      December 12, 2024
    • Performance Testing Newsletter, Q1 Edition
      April 16, 2024
    • New Sheriffing feature and significant updates to KPI reporting queries
      December 13, 2023
    • The Firefox Profiler team was at FOSDEM 2023
      February 27, 2023
    • What’s new with the Firefox Profiler? (Q3 2022)
      October 27, 2022

    Page Load

    • Another Step in Automating the Pageload Recordings
      January 27, 2022
    • Upgrading Page Load Tests to Mitmproxy 7
      November 19, 2021
    • Improving Firefox Page Load
      June 12, 2020

    Tooling

    • The Road to Better Performance Profiles
      February 3, 2026
    • Introducing the Chrome Extension for the Firefox Profiler
      December 12, 2024
    • Announcing PerfCompare: the new comparison tool !
      October 16, 2024
    • Performance Tools Newsletter (Q3 2021)
      November 15, 2021
    • Performance in progress
      August 5, 2021

    Data

    • New Features in Mach Try Perf
      October 26, 2023
    • Ancient Bug Discovered in the Visual Metrics Processing Script
      March 3, 2023
    • Improving the Test Selection Experience with Mach Try Perf
      February 28, 2023
    • Reworking our Visual Metrics Processing System
      July 11, 2022
    • Using the Mach Perftest Notebook
      November 12, 2020

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