Convert SUB to SBV
Drop a .sub file and download it as .sbv. Free, instant, and nothing is uploaded.
MicroDVD .sub
MicroDVD (.sub) times subtitles in video frames instead of seconds, so the frame rate of the video must be known to convert it accurately.
YouTube SBV .sbv
SBV (.sbv) is the caption format YouTube exports from its editor: a start and end time separated by a comma, then the text.
What changes when converting SUB to SBV
- Times are converted between frames and milliseconds with the frame rate you set. Check it against the video, or the subtitles will drift.
- Line breaks inside a cue are kept.
Supported formats
Every format converts to every other. Formatting is kept where the target supports it.
| Format | Extension | Support | Formatting | Notes |
|---|---|---|---|---|
| SubRip | .srt | Read and write | Italic, bold, underline | The safe default when you are not sure what a player needs. |
| WebVTT | .vtt | Read and write | Italic, bold, underline | Cue position and alignment settings survive VTT to VTT. |
| Advanced SubStation Alpha | .ass | Read and write | Full ASS styling | Reads .ssa too. Writes a single default style at 1080p. |
| YouTube SBV | .sbv | Read and write | None | SubViewer .sub files are read as SBV. |
| MicroDVD | .sub | Read and write | None | Needs the frame rate. A wrong value makes subtitles drift. |
| TTML / DFXP | .ttml | Read and write | Italic, bold, underline | Also reads .dfxp and .xml. Layout and regions are dropped. |
| LRC lyrics | .lrc | Read and write | None | No end times. Each cue ends where the next begins. |
| JSON | .json | Read and write | None | Reads {start, end, text} arrays and Whisper segments. |
| Plain text | .txt | Write only | None | Output only. Timing is discarded. |
Private by design
Parsing and conversion run in your browser with JavaScript. Files are read locally and never uploaded, so there is nothing to delete afterwards.
Exact timing
Timestamps convert to the millisecond. MicroDVD uses the frame rate you set, and ASS rounds to the centiseconds it supports.
Fix sync as you go
Shift every cue earlier or later in milliseconds, and strip formatting tags when a player shows them as raw text.
Questions
Is CaptionConvert free?
Yes. There are no limits, accounts or watermarks. Convert as many files as you like, as often as you like.
Are my subtitle files uploaded anywhere?
No. The conversion runs in your browser with JavaScript. Files are read on your device and nothing is sent to a server, so there is nothing to delete afterwards.
What is the difference between SUB and SBV?
MicroDVD (.sub) times subtitles in video frames instead of seconds, so the frame rate of the video must be known to convert it accurately. SBV (.sbv) is the caption format YouTube exports from its editor: a start and end time separated by a comma, then the text.
Is formatting kept when converting SUB to SBV?
MicroDVD has no formatting tags, so there is nothing to lose. Timing is converted exactly.
How do I fix subtitles that are out of sync?
Use the Shift field. Enter a positive number of milliseconds to delay every cue, or a negative number to bring them earlier, then download. 1000 ms is one second.
Which frame rate should I use?
The frame rate of the video the subtitles were made for. 23.976 (film), 25 (PAL) and 29.97 (NTSC) are the common values. MicroDVD files often declare it on their first line, and CaptionConvert picks that up automatically.