Captions for prerecorded audio / video

Silktide tests whether the audio and video players on your pages declare a captions track. Captions let people who are deaf or hard of hearing follow recorded media.

<!-- Problem: no captions track declared -->
<video>
    <source src="intro.mp4" type="video/mp4">
</video>

<!-- Fixed: captions provided as a track -->
<video>
    <source src="intro.mp4" type="video/mp4">
    <track kind="captions" src="intro.vtt" srclang="en" label="English">
</video>

Why this matters

Without , recorded media is inaccessible to people who are deaf or hard of hearing. Good captions carry all the dialogue, identify speakers when it is not obvious, and note meaningful sounds such as music, laughter, or alarms.

Captions also help far beyond their primary audience: people watching in noisy or sound-off environments, people following a second language, and search engines indexing your content.

How to fix it

Create a caption file for each piece of media. Captioning services and speech-to-text tools make this inexpensive, but review automatic captions for errors - they are not yet accurate enough to trust unedited.
Attach the captions with a <track> element inside the player, as in the example above.
For media hosted on an external video platform, enable captions there and embed the platform's player rather than linking straight to the raw video.
If a reported player carries no meaningful audio - it is silent or purely ambient - captions are not required; the finding.

How Silktide tests this

Find the video and audio players in each page's own , skipping any elements you have excluded from checking.
Ignore media that is permanently muted, which cannot be conveying audio information.
Report each player that does not include a <track> element, showing the media's first source file.
Also report links that go directly to videos on known external video platforms, where Silktide cannot confirm captions are available.

Troubleshooting

My captions are burned into the video

Captions baked into the picture ("open captions") are not machine-readable, so Silktide cannot detect them - and they cannot be turned off, resized, or read by braille displays. They do help viewers, so if you have verified them, approve the finding; prefer a separate captions track for new media.

The player shows captions but is still flagged

Some players load captions through scripts rather than a <track> element in the page's HTML, which Silktide cannot see. If you have confirmed captions work in the player, approve the finding.