Captions

Captions are textual representations of audio content, displayed synchronously with video, film, or other media to convey spoken dialogue and relevant non-speech sounds.

Captions can be closed (toggleable via a decoder or player) or open (burned into the video). They are distinct from subtitles, which typically translate dialogue for viewers who do not understand the language; captions include non-speech information such as sound effects, speaker identification, and tone.

There are also image captions, brief descriptions accompanying images or figures in print or on the web; in scholarly publishing, captions explain figures, tables, or diagrams.

Formats and creation: Common caption formats include SRT and WebVTT for online media, TTML/DFXP used in broadcasting; live captions produced in real time by stenographers or automatic speech recognition.

Accessibility: Captioning improves accessibility for deaf and hard-of-hearing audiences and for people in noisy environments; many jurisdictions require captioning on broadcast content or online streaming; guidelines include WCAG and the FCC/Ofcom rules.

Usage considerations: Accuracy, proper timing, line length, punctuation; include speaker labels when needed; avoid obstructing on-screen action.

In publishing, captions provide contextual information for images and figures; in HTML, the figcaption element provides captions for figures.