Closed Captioning

Closed captioning is a term describing several systems developed to display text on a television or video screen to provide additional or interpretive information to viewers who wish to access it. Closed captions typically display a transcription of the audio portion of a program as it occurs (either verbatim or in edited form), sometimes including non-speech elements.


The term "closed" in closed captioning indicates that not all viewers see the captions—only those who choose to decode or activate them. This distinguishes from "open captions" (sometimes called "burned-in" or "hardcoded" captions), which are visible to all viewers.

Most of the world does not distinguish captions from subtitles. In the United States and Canada, these terms do have different meanings, however: "subtitles" assume the viewer can hear but cannot understand the language or accent, or the speech is not entirely clear, so they only transcribe dialogue and some on-screen text. "Captions" aim to describe to the hearing-impaired all significant audio content—spoken dialogue and non-speech information such as the identity of speakers and, occasionally, their manner of speaking—along with music or sound effects using words or symbols.

The United Kingdom, Ireland, and most other countries do not distinguish between subtitles and closed captions, and use "subtitles" as the general term—the equivalent of "captioning" is usually referred to as "Subtitles for the hard of hearing". Their presence is referenced on screen by notation which says "Subtitles" or previously "Subtitles 888" (the latter is in reference to the conventional teletext channel for captions).