Video Needs Captions

Element Code: IM-005

What "Video Needs Captions" actually flags

This check looks for a video element on the page (native HTML5 video, or an embedded YouTube or Vimeo player) that has no associated caption or subtitle track. Specifically it is looking for a <track kind="captions"> element on native video, or, for embeds, evidence that captions exist on the hosted platform, such as YouTube's caption menu being populated. A transcript link sitting somewhere else on the page does not satisfy this, and neither does auto-generated captions that were never reviewed, though auto captions are better than nothing as a starting point.

People often conflate captions, subtitles, and transcripts, and the distinction matters here. Subtitles assume the viewer can hear the audio and just need the dialogue translated or written out. Captions include dialogue plus non-speech audio information like "[phone ringing]" or "[tense music]", because they are built for viewers who cannot hear the audio at all. This check is about captions in that fuller sense, since that is what's required for genuine accessibility compliance.

Why this matters, beyond the compliance box-check

Start with the legal and ethical baseline. WCAG 2.1 Success Criterion 1.2.2 requires captions for prerecorded synchronized media at Level A, the minimum conformance level referenced by the ADA, Section 508, and the EU's European Accessibility Act. If your site serves US or EU users and video is a meaningful part of your content, uncaptioned video is a real legal exposure, not a theoretical one. Website accessibility lawsuits citing missing video captions have been filed against companies of every size.

Then there is the audience you are losing regardless of legal risk. A large share of video consumption on mobile happens with the sound off, in offices, on transit, in bed next to a sleeping partner. Meta has reported similar patterns for its own platforms for years, and the same logic holds everywhere. If your product demo or explainer video is silent-first for a big chunk of viewers and there is no caption text, you are asking them to either turn on sound in an inappropriate setting or scroll past. Most scroll past.

Finally, there is the SEO angle, which is where this check earns its place in an SEO tool. Search engines cannot watch or listen to your video. What they can crawl is text. A properly formatted caption file (typically WebVTT or SRT) gives Google actual indexable text tied to timestamps in your video, which can surface in video search results, help the page rank for phrases spoken in the video but not written elsewhere on the page, and even generate key moments in Google's video results. No captions means your video is functionally invisible to text-based crawlers beyond its title and description metadata.

How to detect missing captions

• View source / DevTools: inspect the video element for a <track> child tag. If it is absent on a native HTML5 video, captions are not wired up regardless of what plays in the UI.
• Screaming Frog: use a custom extraction rule to flag <video> tags across a crawl that lack a sibling <track kind="captions">, so you get a sitewide list instead of checking pages one by one.
• YouTube/Vimeo embeds: open the player, click the CC button. If it is grayed out or missing, no caption track exists on the host platform, and no amount of on-page markup fixes that, the fix has to happen at the source video.
• Manual audit with sound off: literally mute your speakers and watch your own key videos. It is the fastest way to feel the problem the way a chunk of your real audience experiences it.
• Lighthouse / axe DevTools: both flag missing captions as an accessibility violation and will point at the specific element in the DOM.

How to fix it, step by step

1. Get an accurate transcript. Auto-generate one with YouTube's built-in tool, Otter.ai, or Descript, then have a human review it, because auto-transcripts routinely mangle product names, numbers, and technical terms.
2. Convert the reviewed transcript into a timed caption file in WebVTT (.vtt) or SRT format. Most transcript tools export directly to one of these formats.
3. For native HTML5 video, add <track kind="captions" src="captions.vtt" srclang="en" label="English" default> inside the <video> tag.
4. For YouTube, upload the .srt or .vtt file under Subtitles in YouTube Studio and publish it, do not rely on YouTube's automatic captions alone for anything customer-facing without reviewing them first.
5. For Vimeo, upload captions under the video's Settings > Distribution > Captions and Subtitles panel.
6. Re-run your accessibility scan and confirm the caption track is present and the CC button is active, then spot-check timing accuracy against the actual audio.

Caption workflow, at a glance