Regarding Web Vitals measurement in video players

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Zack Haigh

Aug 31, 2021, 8:45:06 PM8/31/21
Hi all!

The Player Team at JW Player has done extensive work around modifying our front end to optimize for Web Vitals score as it will soon become an official Google ranking factor. There are however some instances where score is penalized for what could be considered good UX that may warrant further discussion For example:

- When a user interaction (ie. a click) results in a CLS penalty because an animation delays the layout change beyond the 500ms threshold (for example in an infinitely paginating shelf that pre-renders the next set of items ahead of time).

- Transition between two player UI states (ie. ad playback has different requirements than standard content playback, so we show a different set of controls for each) resulting in a CLS penalty.

- Floating a player element on scroll (we've come up with a workaround for this one but it is less performant than the original implementation and relies and toggling display to none before beginning the animation).

I'm curious if these are unintended penalties, and if so what we can contribute to the conversation regarding the UX impact of dynamic UI in video players. In any case, thanks for reading and looking forward to hearing back from you!



Zachary Haigh

Senior Software Engineer

Annie Sullivan

Sep 1, 2021, 8:46:37 PM9/1/21
to Zack Haigh,
Hi Zack,

Thanks for getting in touch!

Do you have some simple pages that illustrate these issues we could take a look at? They mostly sound like they might be related to layout-inducing animations (see, but it would help us understand better to see some examples.


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