SUB to SRT converter
Two different formats share the .sub extension. MicroDVD stores frame numbers in braces, like {75}{198}, so it can only be converted if you know the video frame rate. SubViewer stores real timestamps and converts directly. This tool detects which one you have and handles both.
Drop your .sub file here
or click to choose — the file stays in your browser
Free, no sign-up, no file size games. The conversion runs in your browser — your subtitles are never uploaded to a server.
How to convert SUB to SRT
- 1Drop your .sub file onto the box above.
- 2If the file is MicroDVD, set the frame rate of the video it was made for — 23.976, 25 and 29.97 cover most cases.
- 3Download the .srt file.
Questions about SUB and SRT
Why does a SUB file need a frame rate?+
MicroDVD stores when a subtitle appears as a frame number, not as a time. Frame 75 is three seconds into a 25 fps video but 3.13 seconds into a 23.976 fps one. Pick the wrong rate and the whole file drifts.
How do I find the frame rate?+
Check the video file properties, or open it in VLC under Tools then Codec Information. Films are usually 23.976 or 24, European broadcast is 25, and North American broadcast is 29.97.
My .sub has no braces — will it still work?+
Yes. That is the SubViewer flavour, which stores timestamps like [00:01:02] and needs no frame rate at all.
What about IDX/SUB image subtitles?+
Those are not supported. A .sub paired with an .idx file contains bitmap images of the subtitles, not text, and needs OCR rather than conversion.
Need to translate the subtitles too?
Converting a format keeps the same language. To translate subtitles into another language while the timing stays exactly where it is, the Mac app does it in batch across 100+ languages, with an editor and validation before export.
Subtitle Translator for macOS