Add your SUB file
Drop one or more .sub files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Converting a .sub file to .srt extracts the document's content from its office package into a portable form. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Converting a .sub file to .srt extracts the document's content from its office package into a portable form. A .sub file in the MicroDVD convention is a frame-based subtitle list: every line reads {startFrame}{endFrame}text, with a pipe character separating the lines inside one cue. Because the timing is expressed in frames rather than milliseconds, a MicroDVD file only means anything alongside the frame rate of the video it was timed to.
A .srt file is a SubRip subtitle document: numbered cues with start and end timestamps and plain caption text. It is the most common caption sidecar for video players, editors, and streaming toolchains that need a simple, widely understood text format. For this route the practical draw is universally understood by media players and editors and human-editable in any text editor — balanced against no standard support for advanced styling, voices, or regions, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .sub, meaningless without the correct frame rate; the wrong value drifts the whole file. Switching to .srt buys you universally understood by media players and editors, which is why it is the better fit for delivering captions alongside MP4 or MKV downloads. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | MicroDVD subtitles (.sub) | SubRip subtitles (.srt) |
|---|---|---|
| Format type | Text-based — characters and structure, so there is no visual quality loss | Text-based — characters and structure, so there is no visual quality loss |
| How it stores data | each cue is one line: {startFrame}{endFrame} followed by the text, with | separating multiple display lines | cues are blocks of an index, a timecode arrow line (HH:MM:SS,mmm --> HH:MM:SS,mmm), one or more text lines, and a blank separator |
| Strongest at | playing back subtitles that were timed against a specific video rip | delivering captions alongside MP4 or MKV downloads |
| Weak spot | meaningless without the correct frame rate; the wrong value drifts the whole file | no standard support for advanced styling, voices, or regions |
Drop one or more .sub files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .srt in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if SRT is selectable, the route is real and validated.
Press Convert. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid SRT file. Outputs keep the original filename with the .srt extension.
There is no visual quality to lose — sub is text-oriented and srt is text-oriented, so the question is structural fidelity. Text, ordering, and basic structure are preserved; complex layout, embedded objects, and styling beyond the target's model are simplified.
Yes — the .sub file is processed inside your browser tab and never uploaded. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded. Close the tab and the file is gone from memory.
VLC, MPC-HC, PotPlayer, Premiere, HandBrake, YouTube, and virtually every desktop player ingest .srt. Browser video elements usually prefer WebVTT, so conversion is common for web delivery.
It depends on the content: cues are blocks of an index, a timecode arrow line (HH:MM:SS,mmm --> HH:MM:SS,mmm), one or more text lines, and a blank separator. Convert one representative file first and compare before batch-processing a large set.
In .sub, there is no metadata section; the only header-like content is the frame-rate declaration, which is read on input and written on output. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .sub → .srt → .sub is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.