Convert SUB to SRT

Convert SUB to SRT. Pick your video's frame rate and MicroDVD frame numbers become real SRT timestamps. Runs in your browser, nothing is uploaded.

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What is a MicroDVD .sub file?

MicroDVD .sub stores each cue as a start frame and an end frame, written {startFrame}{endFrame}text, instead of a clock time. A vertical bar splits a cue into lines. The format is common with older DivX and Xvid AVI releases and old subtitle archives.

How to convert SUB to SRT

Drop the .sub file above and choose the frame rate from the list: 23.976, 24, 25, 29.97 or 30. Press Convert to SRT and download the file. Every frame number is divided by the frame rate to get a time in seconds, which is written as an SRT timestamp. Vertical bars become line breaks and the cues are numbered from 1.

Why the frame rate matters

MicroDVD counts frames, so converting to a time-based format like SRT needs the video's frame rate. With the wrong fps, the subtitles drift further out of sync the longer the film runs. Choosing 25 instead of 23.976 makes each cue land about 4 percent too early, which is nearly five minutes off by the end of a two-hour film.

How to pick the right fps

Match the frame rate of the video the subtitles were made for. Common values are 23.976 for film, 25 for PAL and 29.97 for NTSC. Check the video's properties in your player, for example under Tools, Codec Information in VLC. If the subtitles start in sync but drift, try the other common rates.

Before you start

Input: SUB. Output: SubRip. The settings appear before anything runs, so you can check them first. Your original file is never changed.

A document conversion may not keep every font, layout rule, embedded object, subtitle cue or app-specific feature. Read through the full result before you send or submit it.

Keep the original until you have opened and checked the result. The work happens in this browser tab, so the size you can handle depends on your device's memory, your browser and the file itself.