The anatomy of an SRT file
1
00:00:01,000 --> 00:00:03,500
Welcome to the channel.
2
00:00:03,600 --> 00:00:06,200
Today we are fixing wrong accents
in captions.
| Part | Rule |
|---|---|
| Number | Starts at 1 and counts up |
| Time line | HH:MM:SS,mmm --> HH:MM:SS,mmm with a comma before milliseconds |
| Text | One to two lines; line breaks stay inside the block |
| Separator | One blank line between blocks |
| File | Extension .srt, encoding UTF-8 |
Method 1: write it by hand
- Open a plain text editor (not a word processor).
- Type the blocks as shown above, with times that match your video.
- Save with the extension .srt and choose UTF-8 as the encoding.
- Test the file in the editor or platform you plan to use.
This is fine for a few lines. For a ten-minute video it is slow and easy to get wrong.
Method 2: create it from audio or video
Automatic creation has three steps: get a transcript with timestamps, split it into readable captions, and export it as SRT.
With TooLongToListen:
- Open TooLongToListen and drag in your video or audio. For video, the app extracts the audio in your browser and the video stays on your device.
- Tick the option to generate subtitles (SRT and VTT).
- Sign in with Google and start. The free plan includes 10 minutes at sign-up.
- Download the .srt file when it is ready.
The app splits the text into captions of at most 2 lines of 42 characters, 1 to 7 seconds each, with no overlap. The speech model detects the spoken language automatically; Portuguese is our main focus, so review other languages carefully. See the SRT generator page for details.
Rules that make subtitles easy to read
| Rule | Value |
|---|---|
| Characters per line | at most 42 |
| Lines per caption | at most 2 |
| Reading speed, adult programs | up to 20 characters per second in one public English style guide |
| Breaks | after punctuation, before conjunctions and prepositions |
| Duration | long enough to read, short enough not to linger |
Check the numbers in your own file with the subtitle reading speed checker, and read subtitle reading speed explained.
Check the file before you use it
| Check | Why it matters |
|---|---|
| Open in a text editor | You should see readable letters, not "é" |
| Time lines | A dot instead of a comma breaks some editors |
| Overlaps | Two captions on screen at once confuse players |
| Numbering | Skipped numbers can fail in strict importers |
The SRT validator checks these and lists the line numbers. If accents are wrong, see SRT encoding explained.
Where to use your SRT
- CapCut: import an SRT file into CapCut.
- YouTube: upload an SRT file to YouTube.
- Short videos: TikTok and Instagram do not generally accept a caption file, so editors burn captions in; see auto captions for Reels, TikTok and Shorts.
- Other formats: SRT vs VTT.
Make your SRT now
Use the SRT generator with a short clip first. 10 free minutes at sign-up, no card.
Sources
- SubRip format overview: https://en.wikipedia.org/wiki/SubRip
- English (USA) Timed Text Style Guide: https://partnerhelp.netflixstudios.com/hc/en-us/articles/217350977-English-Timed-Text-Style-Guide
- RFC 3629, UTF-8: https://www.rfc-editor.org/rfc/rfc3629
Frequently asked questions
What is an SRT file?
An SRT (SubRip) file is a plain text subtitle file. Each entry has a number, a start and end time, and one or two lines of text. Almost every video editor and platform can read it.
How do I make an SRT file from a video?
Transcribe the audio with timestamps and export the result as SRT. With TooLongToListen you drop in the video, tick the subtitles option, transcribe and download the .srt file.
Can I write an SRT by hand?
Yes. Open a text editor, write numbered blocks with a time line and text, and save the file as .srt in UTF-8. It works for a few lines but is slow for long videos.
What is the correct time format in SRT?
Hours, minutes, seconds, a comma, then milliseconds: 00:00:01,000 --> 00:00:03,500. Using a dot instead of a comma is a common cause of import failures.
How many characters should a subtitle line have?
A public English style guide for timed text uses at most 42 characters per line and 2 lines. TooLongToListen follows that limit when it splits your text.
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