Glossary
What are open captions?
By the KeyMo team · Updated
Open captions are captions that are always displayed and cannot be turned off, because they are part of the picture itself. Closed captions can be switched on or off by the viewer. The W3C describes open captions as, for example, images of text embedded in the video. KeyMo's captions are open captions.
Open captions meaning in video and cinema
Open captions are text that has been burned into the video frames. The W3C's WCAG note says open captions cannot be turned off, and gives captions that are images of text embedded in the video as an example. Most captions on the web are closed: the viewer can show or hide them.
The cinema meaning follows the same idea. An open-captioned screening shows the words on the main screen for everyone in the room, so nobody can switch them off. Cinema chains describe their own screenings on their own listings; we have not read any chain's policy, so check the cinema's page.
| Point | Open captions | Closed captions |
|---|---|---|
| Viewer can turn them off | No | Yes |
| Where the text lives | In the picture | In a separate caption track or file |
| Survives re-uploading | Yes, they are part of the pixels | Only if the caption file travels with the video |
| Fixing a typo later | Re-export the video | Edit the caption file |
What the rules say
WCAG 2.2 requires captions for prerecorded audio in synchronised media at Level A. The W3C's Understanding document lists providing open, always-visible captions as a sufficient technique, next to closed captions. In the United States, the federal rule for TV captioning (47 CFR 79.1) states that open captioning may be used in place of closed captioning. This is not legal advice; read the source for your situation.
The same W3C pages warn that automatic captions usually need significant editing, and that missing one word such as "not" can reverse the meaning. With open captions this matters more, because the mistake is baked in until you export again.
When open captions are the right choice
- Short vertical clips that will be reposted to several apps. The captions go wherever the file goes, with no caption file to upload.
- Clips that must make sense with the sound off.
- Viewers who would not look for a caption button.
- Not for: workflows that need a separate SRT or WebVTT file, or viewers who want to hide captions. See closed captions and captions vs subtitles.
Common mistakes
- Burning in a transcript nobody proofread.
- Covering faces or key graphics. WCAG notes that captions should not obscure relevant information in the video.
- Placing the text where the app interface will cover it; see safe zone.
- Low contrast against a busy background.
- Expecting a caption file from a video whose captions are pixels. The text has to come from the transcript, not the video.
Where KeyMo touches it
KeyMo draws its captions into the exported clip, so they are open captions. There are 12 styles, they appear word by word, and you can choose no captions. This page does not claim a separate caption-file export. For a permanent version of the same idea, see subtitles added permanently.
Sources: Web Content Accessibility Guidelines 2.2 (W3C) (checked 11 October 2026); Captions (W3C Web Accessibility Initiative) (checked 11 October 2026); Understanding Success Criterion 1.2.2 Captions (Prerecorded) (W3C) (checked 11 October 2026); 47 CFR 79.1 Closed captioning of video programming (eCFR) (checked 11 October 2026).