AI Subtitle Studio
Free tool

Convert MicroDVD (.sub) to SRT

MicroDVD times its cues in video frames, not seconds — pick the right frame rate and this converts it to a normal, time-based SRT.

Nothing stored afterward No account needed MicroDVD (.sub) → SRT (SubRip)

Only used if the file itself has no frame-rate hint in its first cue. Common values: 23.976 (film), 25 (PAL), 29.97 (NTSC).

Your file is processed and sent straight back — never saved on our servers.

Prefer not to upload your file?

The AI Subtitle Studio desktop app has this same Tools section built in — plus AI transcription, translation and batch processing for a whole season at once, all running locally on your Mac or PC.

Get the desktop app
How it works

Upload MicroDVD (.sub), get SRT (SubRip) back

Upload one file

MicroDVD (.sub) — .sub.

Converted instantly

Parsed and rewritten as SRT (SubRip) in memory, no queue and no waiting.

Download the result

The converted file downloads straight to your device.

About this conversion

Converting MicroDVD (.sub) to SRT (SubRip)

MicroDVD is an older subtitle format that survives mostly as .sub files from older rips and subtitle packs — easy to confuse with the unrelated VobSub .sub/.idx pair, which is an entirely different, image-based format. You can tell them apart by opening the file in a text editor: a MicroDVD file is plain text starting with lines like {0}{75}Hello there; a VobSub .sub is binary and unreadable as text, and always comes with a matching .idx file.

The number in each pair of braces is a frame number, not a timestamp — MicroDVD was built for an era of frame-accurate video editing rather than absolute time. To convert it correctly, this tool needs the video's actual frame rate: get it wrong and every cue will drift further out of sync the longer the video runs, since the error compounds with every frame. Some MicroDVD files include a frame-rate hint as their very first line (a lone number with no real dialogue, like {1}{1}23.976) — when present, this converter uses that automatically and the frame rate field below doesn't matter.

FAQ

Questions about this converter

How do I know my video's frame rate?
Common values are 23.976 (film, most modern digital releases), 25 (PAL) and 29.97 (NTSC). Most video players and media info tools (VLC: Tools → Codec Information) show it directly.
What if I pick the wrong frame rate?
Every cue times out slightly wrong, and the error grows across the file — dialogue near the start may look fine while a later scene drifts by several seconds. If the result looks off, try the file again with a different frame rate.
My .sub file won't convert at all — is it definitely MicroDVD?
Open it in a text editor first. If it's unreadable binary data, it's actually a VobSub image-based track (paired with a .idx file) — a completely different, picture-based format that needs OCR, not frame-rate conversion.
What happens to MicroDVD style codes like {y:i}?
They're stripped. SRT has no equivalent for MicroDVD's inline styling codes, so the dialogue comes through as plain text.
Is there an API for this?
Yes — see the API reference for the microdvd-to-srt endpoint, including the fps parameter.
More converters

Related tools and guides

SAMI (.smi) → SRT (SubRip)

SAMI subtitles time each cue by when the next one starts, not by their own end time — this works that out and writes a normal SRT.

MPL2 → SRT (SubRip)

MPL2 times its cues in tenths of a second — this converts that timing to SRT's format and keeps every line.

ASS/SSA (Advanced SubStation Alpha) → SRT (SubRip)

Turn a styled .ass or .ssa subtitle into plain SubRip — dialogue and exact timing kept, fonts, colors, positioning and karaoke stripped since SRT can't hold them.

How to convert any subtitle format to SRT

One offline tool that converts 30+ subtitle formats to SRT: TTML/DFXP, SAMI/SMI, STL, SCC, MicroDVD, MPL2, SubViewer, LRC, SBV and more — with automatic encoding detection.

How to convert SUB/IDX (VobSub) subtitles to SRT

Convert DVD VobSub subtitle pairs (.sub + .idx) into editable SRT files with OCR — extract from MKV or convert standalone files, offline on Windows and macOS.