Reference · SubRip
What is an SRT file?
An SRT file is a plain-text subtitle document: numbered cues, each with a start time, an end time and a line of dialogue, read by a player alongside the video. All of it is visible in a text editor, which is where this guide starts — then editing, the platforms that accept it, the DVD-ripper behind the name, and the WebVTT comparison.
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What is inside an SRT file
Open one in any text editor and the whole format is visible in ten seconds. Cues are stacked one after another, separated by a blank line, and each cue has three parts: a sequence number on its own line, a timing line reading 00:00:12,400 --> 00:00:15,900, and one or two lines of dialogue. Times are absolute — hours, minutes, seconds and milliseconds counted from the start of the video — which is why a SubRip track survives a change of frame rate that would wreck an older frame-based format.
There is no header, no metadata, no language tag and no styling section. Some players honour inline <i>, <b> or <font color> tags inside the dialogue, but none of that is guaranteed, and nothing in the format says where on screen a caption should sit. If the words matter more than the timings, strip the numbers and timecodes out in one pass.
Opening and editing one
Notepad, TextEdit or VS Code opens it instantly, and VLC attaches one to a video the moment you drag it onto the window. For real work — shifting every cue by 400 milliseconds, fixing overlaps, splitting a long caption — a dedicated editor such as Subtitle Edit or Aegisub pairs the cue list with a waveform.
Two practical traps are worth knowing. Encoding is the first: SubRip predates the UTF-8 era, so archived tracks are often saved in Windows-1252 or another local code page and arrive as question marks, which re-saving as UTF-8 cures. Naming is the second: most players auto-load a track only when it shares the video’s base name, as with lecture-04.mp4 and lecture-04.srt in one folder.
Where SRT files work
Almost everywhere, which is the format’s entire argument. Desktop and media-centre players read it — VLC, mpv, Plex, Kodi — and so do smart-TV apps. Editing suites import it onto a caption track: Premiere Pro, DaVinci Resolve, Final Cut Pro, CapCut. Publishing platforms take it on upload: YouTube Studio, Vimeo, Facebook, most learning-management systems. HandBrake and ffmpeg can burn the cues permanently into the picture when a platform carries no separate track at all. The one obvious exception is the browser, where an HTML5 <video> element will not read SubRip — which is what converting the document to WebVTT for the browser is for.
Why it looks so bare
The format is named after SubRip, a Windows program from the early 2000s that ripped subtitles off DVDs by running optical character recognition over the picture. Its output had to be readable, editable and trivial to parse, so it got numbers, timings and text and nothing else. It was never standardised: no specification to cite, no registered MIME type, no official answer on whether markup is allowed. Every player simply agreed to accept it, which is why a twenty-year-old track still opens today — and equally why the format never grew positioning, colour or regions, and why anything richer has to live somewhere else.
SubRip next to WebVTT
WebVTT is the browser-native alternative, and the differences make a short list: it opens with a WEBVTT line, separates milliseconds with a dot instead of a comma, makes cue numbering optional, mandates UTF-8, and adds cue settings, regions and CSS styling. SubRip wins on reach, WebVTT wins on the web, and that is the whole trade. How WebVTT handles the same job covers the other side in the same detail. When the video is already published online, you can save a video’s subtitles as a ready SubRip file without editing anything at all.
Frequently asked questions
What is an SRT file?
A plain-text subtitle document in the SubRip format. It holds numbered cues, each with a start time, an end time and the words spoken in between, and it sits next to a video rather than inside it.
How do I open an SRT file?
Any text editor will do — Notepad, TextEdit, VS Code. For editing with the video in view, Subtitle Edit or Aegisub show a waveform alongside the cue list.
How do I add an SRT file to a video?
Drop it onto a VLC window for instant playback, give it the same base name as the video so players load it automatically, upload it in YouTube Studio or Vimeo, or burn the cues into the picture with HandBrake or ffmpeg.
Can I edit an SRT file in Notepad?
Yes. Keep the blank line between cues, keep the comma before the milliseconds, and save as UTF-8. Those three habits prevent almost every broken track.
What is the difference between SRT and VTT?
SubRip numbers each cue and separates milliseconds with a comma. WebVTT opens with a WEBVTT header, uses a dot, must be UTF-8, and adds styling and positioning for the browser.