myriadfile

SUB (MicroDVD) to SRT converter

MicroDVD .sub files count frames, not seconds. Convert them to time-based SRT with the right frame rate, in your browser.

Runs on your device. Nothing is uploaded.
RunsIn your browser
UploadsNone
CollectionSubtitle tools
Drop a MicroDVD .sub file hereor choose a file: SRT, VTT, ASS/SSA, SBV, SUB, TXTor paste with Ctrl V / ⌘ V
No file loaded yet. Load a sample file

Convert

Choose the output format in the Export box. Plain-text input gets timings generated from reading speed.

Seeing garbled characters such as é or ا? Change the encoding and the file is read again.

Export

Cues

How MicroDVD timing works

A MicroDVD line looks like {1250}{1310}Hello there. The numbers are frame numbers, not times, and a vertical bar separates lines. To know when frame 1250 appears you need the video’s frame rate: at 25 fps it is 50.0 seconds, at 23.976 fps it is about 52.1 seconds.

That is why SUB files go out of sync so easily, and why converting them to SRT, which stores real times, makes them much more reliable. Choose the frame rate that matches the video the subtitles were made for.

How to convert SUB to SRT

  1. Pick the frame rate. In the Convert panel, set “SUB (MicroDVD) frame rate”. 25 is the default; most film releases are 23.976.
  2. Load the .sub file. If the file’s first line declares a frame rate (for example {1}{1}23.976), that value is used automatically and shown in the file info.
  3. Check sync. Use the Preview tab to play your video with the subtitles. If they drift, try another frame rate.
  4. Download the SRT. Once converted, the timing no longer depends on the frame rate.

Settings explained

SUB (MicroDVD) frame rate
Changing it re-reads the file with the new value. Common values: 23.976 (film releases), 25 (PAL), 29.97 (NTSC video).
Missing end frames
Lines without an end frame are shown for two seconds.

Not every .sub is MicroDVD

The .sub extension is also used by VobSub, which stores subtitles as images alongside an .idx file. Those cannot be read as text. If you see binary rubbish when you open the .sub in a text editor, it is VobSub and needs OCR software.

Troubleshooting

Subtitles drift further out of sync over time
The frame rate is wrong. Try 23.976 if you used 25, or the other way round. You can also fix it after conversion with the frame rate tool.
Text has codes like {y:i}
Formatting codes in braces are removed.

Frequently asked questions

Which frame rate should I choose?

The one of the video the subtitles were created for. If unsure, try 23.976 first for films.

Can I export back to SUB?

No. Myriadfile exports time-based formats only.

Do I need the video?

No, but previewing with it is the fastest way to confirm the frame rate.

What if the file has an FPS line?

It is detected and used automatically.

Are my subtitle files uploaded?

No. Parsing, editing and saving all happen in your browser. Nothing is sent to a server.