Writing Caption Timing Around Speech
Writing Caption Timing Around Speech records a distinct W3C-supported accessibility writing task while keeping implementation mechanics outside the writing guidance.
Time captions so the text is synchronized with the corresponding speech and important audio information.
Key details
Important caveats
Scope Boundary
This guide covers the writing/timing relationship; file formats, player APIs, and timestamp syntax are implementation details outside the content rule.
Further guidance
Content
Associate each caption segment with the time span in which its speech or relevant audio occurs instead of displaying unrelated text too early or too late.
Practical Application
Display each caption with the speech or important sound it represents so users can connect the text to the same moment in the media.
Purpose
Synchronization lets users connect caption text with the same moment of dialogue, action, and sound in the media.
Reader Check
If the caption appeared several seconds earlier or later, could the viewer attach the line to the wrong speaker, action, or sound?
Worked Example
When a speaker says “The train is leaving now,” time that caption to the spoken line rather than displaying it during the previous silent shot.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Captions/Subtitles — W3C WAI (opens in a new tab)World Wide Web Consortium (W3C) Web Accessibility Initiative · W3C WAI guidance that captions are synchronized text alternatives for speech and important audio information, with timing encoded in caption files.