Universal Subtitle Converter
- Free
- No upload
- No watermark
Quick answer
A subtitle converter reads one caption format and writes another. This universal converter auto-detects SRT, VTT, ASS/SSA, SBV, MicroDVD (.sub), TTML/DFXP and LRC, parses them into one common timing model, and re-serialises to whichever format you pick — all in your browser. Because everything routes through a shared model, any input converts to any output, and no file is ever uploaded.
Step by step
How to universal subtitle converter
- 01
Add a subtitle file
Drop any supported file or paste its text. The converter auto-detects the source format; you can override it if a file is mislabelled.
- 02
Choose the output format
Pick your target — SRT, VTT, ASS, SBV, TTML, LRC or plain text. For frame-based .sub, set the frame rate.
- 03
Convert and download
The converted subtitles appear instantly. Download the file or copy the text to your clipboard.
In depth
Which subtitle formats can you convert?
The converter understands the formats you actually meet in the wild, and treats them all as interchangeable because each is parsed into the same internal list of timed cues before being written back out.
| Format | Extension | Timing | Styling | Typical use |
|---|---|---|---|---|
| SubRip | .srt | Milliseconds | Basic tags | Universal, YouTube, VLC |
| WebVTT | .vtt | Milliseconds | Cue settings + CSS | HTML5 web video |
| SubStation Alpha | .ass / .ssa | Centiseconds | Full styling & positioning | Anime fansubs, karaoke |
| SubViewer | .sbv | Milliseconds | None | YouTube exports |
| MicroDVD | .sub | Frames | Inline codes | Old DivX/AVI rips |
| TTML / DFXP | .ttml / .dfxp | Clock or offset | XML styling | Broadcast, Netflix delivery |
| Lyrics | .lrc | Centiseconds | None | Music players, karaoke |
Which conversions lose information?
Timing always survives. Styling does not always survive, because the formats are not equally expressive. Converting a richly-styled ASS file down to SRT discards fonts, outlines and on-screen positioning — SRT simply has no syntax for them — while italics, bold, underline and text colours carry over as <i>, <b>, <u> and <font> tags. Converting up the other way (SRT to ASS) is lossless, because you are only ever adding capability the source did not use.
What about frame-based .sub files?
MicroDVD (.sub) stores each cue as a start and end frame number, not a time. Reading it therefore requires knowing the video’s frame rate: the same file at 25 fps and at 23.976 fps produces different timings. Set the correct rate in the converter and the frames are translated to exact times; if the result drifts, you likely have the wrong rate, which the speed changer can also help diagnose.
Is any file uploaded during conversion?
No. The parser and every writer run in your browser as ordinary JavaScript. Your file is never transmitted — verify it yourself in the Network tab of DevTools. This is the whole point of the tool: subtitle files are frequently confidential, and a converter that uploads them defeats their privacy.
Related subtitle tools
For the two most common single pairs there are dedicated pages: SRT to VTT and VTT to SRT. To fix timing after converting, use the subtitle shifter or open the file in the subtitle editor. When the captions are final, add them to your video.
Your files never leave your device
Processed locally in your browser — nothing is uploaded. You can verify it yourself: open your browser’s developer tools, watch the Network tab, and use the tool — no upload request is ever made.
- No file is ever uploaded to a server
- Works offline after the first visit
- No account, no watermark, no limits
A little more clarity
Frequently asked questions
01Can this convert ASS to SRT?
Yes. It reads SubStation Alpha and writes SubRip. The dialogue and timing convert cleanly, but ASS styling and positioning are dropped because SRT cannot represent them.
02How does auto-detection work?
The converter inspects the file’s content — headers, timestamp shape and structural markers — rather than trusting the extension, which is often wrong. You can override the detected format manually.
03Why does my .sub file have the wrong timing?
MicroDVD .sub is frame-based, so it needs the correct frame rate. Set the frame rate that matches the video and the timings become accurate.
04Does converting between formats change the wording?
Never. Only the container format and timestamp syntax change. The caption text itself is copied through unchanged.
05Can I convert a plain transcript into subtitles?
This tool converts between subtitle formats. To turn an untimed transcript into timed cues, use the text-to-subtitle generator, which spaces cues by reading speed.
06Which format should I choose for a website?
WebVTT. It is the only format the HTML5 <track> element accepts. Choose SRT for VLC, desktop players and YouTube uploads.
07Is TTML the same as DFXP?
Effectively yes. DFXP is a profile of TTML used in broadcast and streaming delivery; the converter reads both and writes standard TTML.
08Are my files uploaded to convert them?
No. All parsing and writing happen locally in your browser. You can confirm there is no upload in the Network tab of your developer tools.
Guides
Further reading
- Guide6 min readSubtitle formats explained: SRT, VTT, ASS, SBV and TTMLSRT, VTT, ASS, SBV and TTML all pair text with time, but they were built for different jobs. Here is what each one is good at and how to pick.Read the guide
- Guide6 min readHow to fix subtitle encoding problems (garbled characters)When accented letters turn into é or ż, the words are fine — the file is just being read with the wrong alphabet. Here is why it happens at the byte level, and how to re-decode and save clean UTF-8.Read the guide
- Guide6 min readHow to convert SRT to VTT (and why HTML5 video needs it)A browser will not play an SRT file, but converting one to the VTT it does accept is almost trivial. Here are the two changes involved, and the exact markup to load the result.Read the guide
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