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Media

What video and audio is on this page, and is any of it captioned?

Media is the heaviest thing on most pages that have any, and the settings that decide the cost - `preload`, `autoplay`, a poster frame that is a full-size JPEG - are attributes nobody looks at twice. Captions are the other reading: a video without them is inaccessible, and an embed’s tracks live in a document this side cannot read, so an embed is never counted as uncaptioned.

Reach itPress ⌘+K on any tab and type media.Ctrl+Kon Windows and Linux

Every video and audio element, and which of them has captions
readsmedia elements, their sources and tracks
writesnothing
sendsnothing
captionscaptions and subtitles tracks only
embedsnever counted as uncaptioned - their tracks are unreadable
posterslisted with their size, and downloadable
planfree
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TWO BUILDS9 browsers

Chromelisting in reviewFirefoxlisting in reviewBravelisting in reviewOperalisting in reviewEdgelisting in review4 moreChromium browsers: Arc, Vivaldi, Chromium, Opera GXthe Chrome build

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section#about

What this actually is

On any page with a player, before shipping a hero video, and as an accessibility check. The download links are also the practical way to get a poster frame out of a page.

section#asked

Asked about this diagnostic

Why is a YouTube embed not marked as uncaptioned?

Because its tracks are inside a document on another origin that nothing here can read. Marking it uncaptioned would be a claim made from an absence of evidence.

What counts as a caption track?

`captions` and `subtitles`. A `descriptions` or `chapters` track is a different thing and counting it would inflate the reading.

Does preload="auto" matter?

On a page with one video, rarely. On a page with six, it is the whole page weight - the browser starts fetching all of them before anybody presses play.

Can I download the video itself?

The source URLs are listed, and a poster is directly downloadable. Whether a stream can be saved depends on how it is served, which is the site’s decision rather than ours.

Add LoupeKit- opens the list of browsers it can be installed in

TWO BUILDS9 browsers

Chromelisting in reviewFirefoxlisting in reviewBravelisting in reviewOperalisting in reviewEdgelisting in review4 moreChromium browsers: Arc, Vivaldi, Chromium, Opera GXthe Chrome build

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