< Platform


Overall Goal

Enable a smooth and responsive user experience for Firefox desktop and mobile users.


Competitive versus other browsers

We believe or have data that hangs, jank, and other forms of poor performance result in users moving to other browsers. [evidence needed]

Competitive versus native

"Both aspects here are important. Making existing content less janky makes it easier to compete against other browsers. Making it easier to create jank-free content makes it easier for the web to compete against native." - jonas

Implementation Strategy

Outstanding Issues

  • How do we work with Firefox Content Performance program
  • What forms of jank are we prioritizing?
  • What are our use cases, projects, sites that we prioritize
  • How do we measure? How do we automate that measure and see our progress over time?

How do we measure

  • Specific use cases with Top-N sites and measure frame rate
  • Video (compositing on-time).
  • Animations (compositing on-time, JavaScript/main thread latency+throughput)
  • WebGL/WebVR (compositing on-time, input latency, main thread latency, and JavaScript¬†throughput).
  • Scrolling (compositing on-time, input latency, and layout/painting).

Sites we care about

Important sites, especially those perform worse in Firefox versus Chrome/Safari/IE.

Borrowed from Content Performance Program


Internal Projects we care about

  • Gaia Team
  • FFOS Team
  • Partner Engineering
  • Games
  • WebVR
  • Shumway

External Projects

And a list of 5 web frameworks that are likely focal points for concerns along these lines.

Identify existing programs that have the same or similar goals

When will they land? If they land did they solve the problem?



  • Product sponsor/driver: naveed
  • Engineering program manager:
  • Platform Teams and Team champions:


  • Technical lead(s):

Communication and Discussions