Convert SUB, ASS, SBV and TTML to SRT

Older subtitle formats store times in video frames (MicroDVD .sub) or have styling that some players can’t read (ASS). Cuemend reads them and writes clean SRT – or any other format.

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MicroDVD .sub to SRT

Open the .sub file in Cuemend. Lines look like {1025}{1090}Text – those are frame numbers.
If the file states its frame rate (a first line like {1}{1}23.976), it is used. Otherwise Cuemend assumes 23.976 and asks you to check: choose your video’s frame rate in the menu above the table.
Save as SRT.

There are two kinds of .sub file. MicroDVD and SubViewer .sub files are text – supported. A .sub file that comes with an .idx file is VobSub (DVD pictures): it needs OCR and is not supported.

ASS / SSA to SRT

Dialogue lines, italics, bold and line breaks are converted; styles, positions and karaoke effects are not part of SRT and are dropped. To keep the styling, edit and save as ASS instead – Cuemend keeps the original header and styles.

Other formats

YouTube SBV, SubViewer, TTML / DFXP (also with frame and tick times) can be read; SRT, VTT, ASS, SUB, SBV, TTML, plain text and CSV can be written.

Questions and answers

My .sub file is binary / won’t open.

Then it is probably VobSub (with an .idx file next to it) – picture-based subtitles. Those need an OCR program such as Subtitle Edit.

The timing drifts after converting a .sub.

The frame rate was wrong. Undo, choose the correct frame rate above the table (or convert it in frame rate), and save again.

Last updated: 2026-10-26