What is a .srt file?
SubRip Subtitle · Video · SubRip (open) · 2000s
SRT is the most common subtitle file. It is a plain-text list of numbered lines, each with a start and end time and the words to show. Put it next to a video with the same name and most players load it automatically.
What is a .srt file used for?
An SRT holds nothing but text and timing: a number, a line saying when a caption appears and disappears (with a --> between the two times), the caption text, then a blank line before the next one. That simplicity is why almost every player, editor and video site accepts it.
The easiest way to use one is to give it the same filename as the video and keep them in the same folder, for example movie.mp4 and movie.srt. Players like VLC then load the subtitles automatically, or you can add them from the player's subtitle menu.
Because it is plain text, you can open and fix an SRT in any text editor, which is handy for correcting a typo or nudging the timing.
SRT carries no styling of its own. For captions with fonts, colours and positioning on the web, WebVTT (.vtt) is used instead.
How to open a .srt file
The .srt format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Any text editor (to edit)
- VLC / players (to display with video)
- Subtitle Edit
macOS
- TextEdit (to edit)
- VLC / IINA (to display)
Linux
- Any text editor
- VLC / mpv
Web
- Upload alongside video; convert to VTT for HTML5
How to convert a .srt file
You can convert a .srt file to VTT, ASS using a conversion tool or the export menu of an app that opens it.
.srt file signature (magic bytes)
Programs recognise a .srt file by the bytes at the start of the file, not by its name. These are the signatures for SRT.
| Hex signature | Offset | Note |
|---|---|---|
| (no fixed signature) | 0 | plain text; numbered cues with HH:MM:SS,mmm --> HH:MM:SS,mmm timestamps |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .srt file?
SRT is the most common subtitle file. It is a plain-text list of numbered lines, each with a start and end time and the words to show. Put it next to a video with the same name and most players load it automatically.
How do I add an SRT subtitle to a video?
Give the .srt the same name as the video (movie.mp4 and movie.srt) and keep them in one folder, then open the video in VLC. Or, in the player, use the subtitle menu to add the .srt manually.
How do I open or edit an SRT file?
Open it in any text editor, such as Notepad or TextEdit. Each caption is a number, a timecode line, and the text. Save as plain text when you are done.
Related formats
Sources
Details on this page were checked against authoritative references: