subtitle

A subtitle is a textual representation of spoken dialogue and, in some contexts, non-dialogue audio cues that is displayed on screen during video playback. Subtitles translate or transcribe dialogue for viewers who do not speak the original language. Subtitles are distinct from captions, which also convey non-speech information such as sound effects and speaker identification. Subtitles can be open, meaning they are always visible, or closed, meaning they can be turned on or off by the viewer through a player.

Subtitles are stored in text-based formats that encode time codes and display rules. Common formats include SubRip (.srt), WebVTT (.vtt), SubViewer, and Advanced SubStation Alpha (.ass/.ssa). Timed text standards such as TTML (Timed Text Markup Language) and WebVTT underpin many streaming and web platforms. For broadcast, captions and subtitles may be delivered in additional formats depending on regional standards and distribution methods.

Creation and editing can be done manually with dedicated software or generated automatically by speech recognition. Editors adjust start and end times, segment dialogue into readable lines, and apply punctuation and speaker labeling as needed. Subtitles may be burned into video or delivered as separate text tracks or streams that players render, sometimes with styling options such as font, color, and position.

Usage spans accessibility, language learning, and international distribution. Subtitles enable the Deaf or Hard of Hearing to access audio content and help non-native speakers follow dialogue. They are essential in streaming services, films, television, and online videos, and are typically accompanied by metadata indicating language, timing, and rights.