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Using the Firefox Profiler for web performance analysis

Nazım Can Altınova�Slides: https://share.firefox.dev/profiler-fosdem-2021

profiler.firefox.com

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about:me

Nazım Can Altınova

Living in Berlin, Germany

Originally from Turkey

Software Engineer at Mozilla,

Performance Tooling team

@canaltinova on Twitter

@canova on GitHub

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Agenda

  1. What is a profiler?
  2. What is Firefox Profiler?
    1. Main advantages
  3. How to capture a profile?
  4. How to capture a good profile?
  5. Firefox Profiler analysis UI
  6. Sharing a profile
  7. Demo
    • Analyzing a performance issue with a big loop.
    • Analyzing a reflow issue.

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What is a profiler?

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Helps developers to analyze performance issues

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And gives insight

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What is Firefox Profiler?

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Old

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New

Recording UI

Analysis UI

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Capture a performance profile.

Analyze it. Share it.

Make the web faster.

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Main advantages

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More information with markers, screenshots, network requests, different visualizations and more.

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Capture a profile, share with an expert.

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How to capture a profile?

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1. Go to profiler.firefox.com

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2. Follow the instructions

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Recording UI

Record with: Ctrl + Shift + 1

Capture with: Ctrl + Shift + 2

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How to capture a good profile?

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Isolate as much as possible

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Make sure you reproduced the results you want

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Re-record until you are happy with the profile data

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Firefox Profiler analysis UI

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Timeline

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Range selection

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Screenshots in the timeline

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Category graph in the timeline

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Markers in the timeline

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Marker

tooltips

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Panels

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Sharing a profile

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Profile sharing panel

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Demo

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Thank you

Firefox Profiler Documentation:https://profiler.firefox.com/docs/

Slides:https://share.firefox.dev/profiler-fosdem-2021

Matrix channel:https://chat.mozilla.org/#/room/#profiler:mozilla.org