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Information about Loading efforts in Chromium

North Star

Loading on the web is user centric, sustainable, fast and delightful.

  • user centric: the experience is described through key user moments or needs, and assessed against a perceptual model of performance.
  • sustainable: a sensible contract between Web developers, UA and users about how a web application loads, with usage of memory / power / data that is proportional to value.
  • fast:
    • First meaningful paint in under 1 second.
    • First meaningful paint for transitions (e.g. back navigation) in under 100ms.
  • delightful:
    • No user-visible reflows after reaching first meaningful paint.
    • Decent response time and scrolling performance after reaching first meaningful paint.
    • First Time to interactive in under 5, and Consistently Interactive under 10 seconds.
    • Response time < 100ms and Scrolling at 60fps after reaching TTI.

These are the
goals we should strive for.
Some aspects might be extremely challenging but making progress toward these is what should drive our work.

How do I find out what's happening?

I have a reproducible bad Loading user experience, what do I do?

  • As a user:
    • File a Speed bug
    • Include the "Loading" keyword in the subject if the issue fits within the scope of the North Star.
    • If you are not sure, don't include the "Loading" keyword, triage will make sure it shows up in the right bucket.
  • As a chromium developer
    • Same steps but try to record a trace (select every trace categories on the left side).

I'm a dev and interested in helping on Loading. How do I get started?

Reach out via loading-dev@ and tell us more about you:
  • share your particular interest and expertise
  • tell us how familiar you are with chromium development
  • point to CLs if not a lot of developers are familiar with your work


Your friendly PM: kenjibaheux
Blink TLs: kinuko, kouhei (blink>loader), falken (blink>worker, blink>serviceworker), yhirano (blink>network)
Chrome TLs: creis (navigation), mattcary (speculative features, optimized loading), clamy (plznavigate)

"Here here!": reach out to kenjibaheux@ if you want your name to be added here.

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