· Guides · 3 min read
Audio Description vs. Closed Captions vs. Subtitles: Understanding Video Accessibility
Audio description, closed captions, and subtitles serve different audiences and different accessibility needs. Here is how they differ and when you need each one.
Video accessibility involves multiple features, each serving a different audience and a different need. The three most common — audio description, closed captions, and subtitles — are often confused but serve fundamentally different purposes.
Quick Comparison
| Feature | For Whom | What It Does | Required By |
|---|---|---|---|
| Audio Description | Blind / low vision viewers | Narrates visual information | EAA, ADA, CVAA, Ofcom |
| Closed Captions | Deaf / hard of hearing viewers | Transcribes all audio (dialogue + sounds) | ADA, FCC, EAA, CVAA |
| Subtitles | Viewers who speak a different language | Translates dialogue only | Varies by market |
Audio Description (AD)
What it does: Provides a spoken narration of important visual information — actions, settings, facial expressions, scene changes, and on-screen text — during natural pauses in dialogue.
Who it serves: People who are blind or have low vision.
How it works: AD is delivered as a separate audio track. Viewers select it through their device’s accessibility settings. The description plays alongside the original audio.
Example:
“The detective enters the dimly lit office. Papers are scattered across the desk. He notices a photograph face-down on the bookshelf and picks it up.”
Key characteristics:
- Describes visual content, not audio
- Inserted during pauses in dialogue
- Requires understanding of narrative context
- Available in multiple languages
Closed Captions (CC)
What it does: Provides a text representation of all audio content — dialogue, speaker identification, music descriptions, and sound effects.
Who it serves: People who are deaf or hard of hearing.
How it works: Text is displayed on screen, synchronized with the audio. Can be turned on or off by the viewer.
Example:
[DETECTIVE MORRISON] I need to see the evidence. [suspenseful music] [phone buzzing] [SERGEANT HAYES] Sir, you’ll want to see this.
Key characteristics:
- Transcribes dialogue with speaker identification
- Includes non-speech audio (music, sound effects)
- Synchronized with video timing
- Same language as the audio track
Subtitles
What it does: Provides a translation of spoken dialogue into another language.
Who it serves: Viewers who speak a different language than the audio track.
How it works: Translated text is displayed on screen, synchronized with the dialogue.
Example (English audio with French subtitles):
Audio: “I need to see the evidence.” Subtitle: “Je dois voir les preuves.”
Key characteristics:
- Translates dialogue only
- Does not include sound effects or music descriptions
- Assumes the viewer can hear the audio
- Different language from the audio track
How They Work Together
Full video accessibility requires all three features working together:
- A deaf viewer who speaks the audio language needs closed captions
- A blind viewer needs audio description
- A hearing viewer who speaks a different language needs subtitles
- A deaf viewer who speaks a different language needs translated captions (SDH — Subtitles for the Deaf and Hard of Hearing)
- A deafblind viewer may use captions with a braille display
WCAG Requirements
WCAG 2.1 specifies different success criteria for each:
| Feature | WCAG Criterion | Level |
|---|---|---|
| Captions (pre-recorded) | 1.2.2 | A (minimum) |
| Audio description (pre-recorded) | 1.2.5 | AA |
| Captions (live) | 1.2.4 | AA |
| Extended audio description | 1.2.7 | AAA |
| Sign language | 1.2.6 | AAA |
Most regulations require Level AA compliance, which means both captions and audio description are mandatory for pre-recorded content.
Common Misconceptions
“Captions are enough for accessibility”: Captions serve deaf and hard of hearing viewers but do nothing for blind viewers. Full accessibility requires both captions and audio description.
“Subtitles and captions are the same thing”: Subtitles translate dialogue. Captions transcribe all audio including non-speech sounds. SDH (Subtitles for the Deaf and Hard of Hearing) bridges both by providing translated text with non-speech audio descriptions.
“Audio description is only needed for movies”: AD is valuable for any video content — educational videos, corporate training, social media content, news programming, sports, and live events.
The Bottom Line
Comprehensive video accessibility requires multiple features serving different audiences. Audio description, closed captions, and subtitles each address distinct needs and are often mandated separately by regulations. Media companies aiming for true accessibility — and full regulatory compliance — need all three.