SRT
SubRip Subtitle
The most common subtitle file format. Plain text with numbered cues and HH:MM:SS,mmm timestamps.
In depth
SRT (SubRip Subtitle) is a plain-text subtitle format created in the late 1990s for the SubRip software. Each cue is a numbered block with a start and end timestamp using comma-separated milliseconds, followed by one or more lines of text. Its simplicity made it the de facto standard for fan-translated subtitles, and today nearly every video editor, media player, and streaming pipeline accepts it.
When to use it
Use SRT when you need maximum compatibility — desktop video editors (Premiere, Final Cut, DaVinci, CapCut), media players (VLC, MPV), and most online platforms (YouTube, Vimeo, Facebook) all read it natively.
Example
1 00:00:01,000 --> 00:00:03,500 Hello world. This is a caption.
Frequently asked
What does SRT stand for?+
SubRip Subtitle. SubRip was the Windows program from 2000 that created the format.
Does SRT support styling?+
Officially no — but many players unofficially recognize HTML-style <i>, <b>, and <font color="…"> tags inside SRT cues. Don't rely on this for cross-platform delivery.
What's the maximum number of lines per cue?+
There's no hard limit, but two lines per cue is the broadcast standard. Anything more is hard to read at typical screen sizes.
The W3C web standard for subtitles. Used by HTML5 <track> elements. Like SRT but with dot-separated milliseconds and styling support.
A heavily-styled subtitle format used by Aegisub and the anime fansub community. Supports per-cue fonts, colors, positioning, and karaoke timing.
Captions that the viewer can toggle on or off, typically delivered as a separate text track encoded into or alongside the video.