Subtitles

Subtitles are on-screen text that conveys spoken dialogue in a film, video, or live program. They can render the original language or provide a translation. In many regions a related feature called captions is used to describe non-speech audio and speaker activity for deaf or hard-of-hearing audiences.

Subtitle data is stored in plain-text formats such as SRT (SubRip), WebVTT, and ASS/SSA, or in timed-text formats like TTML. For broadcast, closed captions in the US use EIA-608/708. Subtitles can be hard-subtitled (burned into the image) or soft-subtitled (a separate data track that can be turned on or off). They rely on timecodes and line breaks to sync with video and may include speaker labels and cues for sound effects. Display position, contrast, font, and line length affect readability.

Creation involves transcription of dialogue, translation when needed, and synchronization with the video timeline. Quality control checks ensure accuracy, timing, punctuation, and proper speaker indication. Tools range from dedicated subtitle editors to automatic speech recognition and machine translation systems. Accessibility and localization goals influence style guides, timing, and character counts.

Subtitles support accessibility, language learning, and global distribution by enabling viewers who do not understand the original language to follow content. They are widely used in films, television, streaming services, educational videos, and online platforms. Regulations in some jurisdictions require captioning for broadcasts and online media, driving ongoing improvements in standards and tools.

Readability considerations include keeping lines short, avoiding long words, presenting clear speaker identification, and limiting on-screen text to safe regions. Common challenges involve accuracy, lag, censorship, and cultural localization.