Intent to Ship: First Paint Timing API

200 views
Skip to first unread message

Shubhie Panicker

unread,
May 11, 2017, 5:55:07 PM5/11/17
to blink-dev, Tim Dresser, Ilya Grigorik

Contact emails

pani...@chromium.org, tdre...@chromium.org, igri...@google.com

 

Spec

https://github.com/wicg/paint-timing

Tag review: https://github.com/w3ctag/design-reviews/issues/177

 

Summary

No single moment in time completely captures the user’s "loading experience". To give developers better insight into the loading experience, we will expose two new key progress metrics that capture the key moments during pageload: First Paint (FP) and First Contentful Paint (FCP).

For detailed motivation for First Paint, see the Why First Paint doc.

 

(In the future, we may expose more such key moments — for example, time to first meaningful paint, time to interactive, etc. — to help developers better understand and optimize the loading experience.)

 

Also, the non-standardized first-paint API (chrome.loadTimes’ firstPaint) has high usage ~0.97%, we cannot deprecate and remove this API without shipping the standardized API.

 

Link to “Intent to Implement” blink-dev discussion

Intent to Implement thread

https://discourse.wicg.io/t/expose-first-paint-timing-in-performance-observer/1868/2

The primary feedback we got was to make the timing more accurate by capturing the cost of the rendering pipeline (compositing, rasterization) -- we have now updated the timing to include time up to the swap.

 

Is this feature supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)?

Yes.

 

Interoperability and Compatibility Risk

Compat risk is none, the event is exposed via well-defined Performance Observer interface.
Interop risk is moderate to low: the cost of the rendering pipeline is implementation-dependent on different browsers.

 

Edge: Public support

Firefox: No signals

Safari: Public support

Web developers: Positive (SOASTA, Facebook, AMP)

 

Is this feature fully tested by web-platform-tests?

 

OWP launch tracking bug

OWP launch tracking bug.

 

Entry on the feature dashboard

https://www.chromestatus.com/feature/5688621814251520


Chris Harrelson

unread,
May 15, 2017, 9:09:29 PM5/15/17
to Shubhie Panicker, blink-dev, Tim Dresser, Ilya Grigorik
LGTM1

--
You received this message because you are subscribed to the Google Groups "blink-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscribe@chromium.org.

TAMURA, Kent

unread,
May 16, 2017, 2:00:29 AM5/16/17
to Chris Harrelson, Shubhie Panicker, blink-dev, Tim Dresser, Ilya Grigorik
LGTM2.


Jochen Eisinger

unread,
May 22, 2017, 7:16:02 AM5/22/17
to TAMURA, Kent, Chris Harrelson, Shubhie Panicker, blink-dev, Tim Dresser, Ilya Grigorik
lgtm3

LGTM2.


LGTM1

To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+...@chromium.org.

--
You received this message because you are subscribed to the Google Groups "blink-dev" group.
To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw8CpZBMuPrMHY4q3wFn0-%2BO1eX6enK-zsuNO3i9SQV%3D9g%40mail.gmail.com.
--
TAMURA Kent
Software Engineer, Google


--
You received this message because you are subscribed to the Google Groups "blink-dev" group.
Reply all
Reply to author
Forward
0 new messages