SUB to SRT converter
Convert a MicroDVD .sub file — the kind with {frame}{frame} timing — into a standard SubRip .srt with real timestamps. Pick the frame rate if needed and download instantly.
100% private. Your files are processed locally in your browser and never uploaded to a server.
Drop your .sub file
or click to browse · converts to .srt instantly
Why .sub files misbehave
MicroDVD .sub files don't store times at all — they store frame numbers, like {25}{100}Hello. A player has to know the video's frame rate to turn frames into seconds, and if it guesses wrong every line lands at the wrong moment, drifting further out as the video plays. Converting to SRT bakes real timestamps into the file once, at the correct frame rate, so it plays properly everywhere and never depends on a player's guess again.
Getting the frame rate right
Some .sub files declare their frame rate in a {1}{1} header line, and the converter reads and uses it automatically. If there is no declaration, it assumes 23.976 fps (the most common movie rate) and tells you so. If the converted subtitles run steadily faster or slower than the video, the assumption was wrong — just pick 25 fps (PAL/European releases) or 29.97 fps (NTSC) from the frame-rate menu and download again.
When this converter is not the right tool
If your .sub file travels with a matching .idx file, it is VobSub, a completely different format that stores images of subtitles ripped from a DVD. Those need OCR software, not a text converter. And if the converted SRT is uniformly early or late (rather than drifting), the source timing was already offset — fix that with the subtitle sync tool.
How to convert SUB to SRT
- Drag your
.subfile into the box above, or click to browse. - The file is converted to SubRip (.srt) instantly, in your browser.
- Check the preview and any warnings, then click Download.
Is my file uploaded anywhere?
No. The conversion runs entirely in your browser using JavaScript. Your subtitle file is never sent to a server, there is no sign-up, and there is no limit on how many files you convert. Need the other direction? Use the SRT to SUB converter.
Other subtitle conversions
Frequently asked questions
How do I convert a SUB file to SRT?
Drop the .sub file into the converter above. If the file declares its frame rate it is used automatically; otherwise pick the rate that matches your video (23.976, 25 or 29.97 fps are the common ones) and download the .srt.
Why is the timing wrong after converting SUB to SRT?
MicroDVD timing depends on frame rate. If subtitles drift steadily earlier or later through the video, the frame rate used for conversion does not match the video. Re-convert with a different rate: 25 fps for European/PAL releases, 23.976 for most films, 29.97 for NTSC.
My .sub file came with an .idx file. Will this work?
No. A .sub + .idx pair is VobSub, which contains pictures of subtitles rather than text. It needs OCR software such as Subtitle Edit on the desktop. This converter handles text-based MicroDVD .sub files.
Is the SUB to SRT converter free, and are my files uploaded?
It is completely free with no sign-up and no file limit. The conversion runs in JavaScript in your browser, so your subtitle file never leaves your device and nothing is stored on a server.