Subtitles vs closed captions
Subtitles assume the viewer can hear the audio but does not understand the language, so they carry dialogue only. Captions assume the viewer cannot hear it, so they add speaker identification and non-speech sound — a door slamming, music playing, someone shouting off-screen. "Closed" means the viewer can switch them off; "open" means they are burned into the picture and cannot be removed.
Last reviewed 2026-09-07
What each one contains
| Subtitles | Closed captions | |
|---|---|---|
| Assumes the viewer | Hears the audio, does not know the language | Cannot hear the audio |
| Dialogue | Yes | Yes |
| Speaker identification | Rarely, only when unclear | Yes — [NARRATOR], [ANNA] |
| Non-speech sound | No | Yes — [door slams], [soft piano] |
| Language | Usually translated | Usually the same as the audio |
| Typical purpose | Localisation | Accessibility and legal compliance |
Closed and open
This is a separate axis from subtitles versus captions, and the two get confused constantly. Closed means the text lives in a separate track or file and the viewer decides whether to see it. Open means it is part of the video frames themselves — always visible, impossible to switch off, and impossible to translate later without re-rendering the video.
SDH — the format that sits between them
SDH stands for Subtitles for the Deaf and Hard of Hearing. It carries caption content — speaker labels and sound descriptions — but is delivered as a subtitle track rather than as broadcast caption data. Streaming services use SDH because their delivery pipeline is built for subtitle files, not for CEA-608 caption streams.
Why the distinction has legal weight
- •In the United States, the FCC requires captions on broadcast television, and the ADA has been applied to online video in court.
- •Section 508 requires captions on federal government content.
- •The EU Web Accessibility Directive and EN 301 549 require captions on public sector video.
- •Translated subtitles satisfy none of these on their own — a Spanish subtitle track does not make an English video accessible to a deaf viewer.
Which do you need
- 1Reaching viewers in another language → subtitles.
- 2Accessibility, or a compliance requirement → captions, in the original language.
- 3Both audiences → captions in the source language plus translated subtitle tracks. This is what streaming platforms ship.
Already have a caption or subtitle file that needs another language?
Translate subtitle filesQuestions
Are subtitles and captions the same thing?+
No. Subtitles carry dialogue for viewers who can hear but do not understand the language. Captions carry dialogue plus speaker identification and non-speech sound for viewers who cannot hear the audio at all.
What does closed mean in closed captions?+
That the viewer can turn them on and off. The text is stored separately from the picture. Open captions are burned into the video frames and cannot be switched off or replaced.
What is SDH?+
Subtitles for the Deaf and Hard of Hearing: caption content — speaker labels and sound descriptions — delivered as a subtitle track. Streaming services use it because their pipelines handle subtitle files rather than broadcast caption data.
Do translated subtitles satisfy accessibility requirements?+
No. Accessibility rules ask for captions that convey the audio to someone who cannot hear it, in the language being spoken. A translated subtitle track serves a different audience and does not replace them.