Add Video Captions

Make videos accessible and watchable without sound.

85% of Facebook videos are watched on mute. Deaf users can’t watch uncaptioned content at all. Captions aren’t just accessibility compliance—they’re reach. Here’s how to add them.

What Type of Captions Do You Need?

Closed captions (CC) can be turned on/off by the viewer. This is the standard for web video and what WCAG requires (Level A) for prerecorded audio.

Open captions are burned into the video itself. Use these for social media where captions don’t always display properly, or when you want guaranteed visibility.

Subtitles are translations for different languages—same concept, different purpose.

For most web video, you want closed captions: viewers can toggle them, and you can update them without re-rendering the video.

Add Captions by Platform

YouTube

YouTube auto-generates captions for free. The accuracy depends on audio quality and speaker clarity—plan to edit them.

1. Upload video → Go to YouTube Studio → Subtitles
2. Let YouTube auto-generate captions (takes a few minutes)
3. Review and edit for accuracy (especially names, technical terms)
4. Or upload your own .srt file if you have professional captions

Vimeo

Vimeo requires a Pro plan for auto-transcription. Otherwise, upload your own caption file.

1. Go to video settings → Distribution → Subtitles
2. Upload .srt or .vtt file
3. Or enable auto-transcription if available on your plan

Self-Hosted Video

For videos on your own server, use the <track> element with a WebVTT file:

<video controls>
  <source src="video.mp4" type="video/mp4">
  <track
    kind="captions"
    src="captions.vtt"
    srclang="en"
    label="English"
    default
  >
</video>

Getting Captions Made

Three approaches, depending on budget and volume:

DIY with auto-captions (free, slower)

Upload to YouTube, let it auto-generate captions, download the .srt file, edit in any text editor, re-upload to your platform. Works for small volumes but editing takes time.

AI transcription services (cheap, fast, needs review)

Otter.ai and similar tools generate transcripts quickly. Good enough for drafts, but you’ll still need human review for accuracy.

Professional transcription (accurate, costs money)

Rev charges $1.50/minute for human transcription. 3Play Media handles enterprise volumes with higher accuracy guarantees. Worth it for important content or legal compliance.

Caption Quality Checklist

Before publishing, verify these basics:

• Timing: Captions sync with audio (no lag or early text)
• Speaker ID: Multiple speakers identified [SARAH:] [JOHN:]
• Sound effects: Non-speech audio noted [door slams] [laughter]
• Music: Background audio indicated [upbeat music] [dramatic sting]
• Readability: No more than 2 lines on screen at once
• Accuracy: Spelling and grammar correct, especially proper nouns

File Formats

.vtt (WebVTT) — Web standard. Use this for HTML5 video. Supports styling.

.srt (SubRip) — Simple and universal. Works almost everywhere. Plain text with timestamps.

.sbv — YouTube’s native format. Similar to .srt but YouTube-specific.

Confirming All Videos Are Captioned

• All videos have accurate captions (not just auto-generated)
• Captions are synced with audio timing
• Caption toggle is visible and works
• Audio descriptions exist for key visual content (if needed)

Sources

• Otter.ai
• Rev
• 3Play Media