SBV is the caption format YouTube Studio hands you when you download subtitles, and almost nothing else reads it. FindUtils SBV to SRT converts it to SubRip in your browser, and back again. The tool does not upload or store your caption file.

This guide explains what the two formats actually differ on, why renaming the file does not work, and how to get the file out of YouTube in the first place.

The Difference Is Small and Total

Both formats are plain text. Both list cues as a timing line followed by the words on screen, separated by blank lines. Put them side by side and the differences are easy to miss:

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SBV (SubViewer)              SRT (SubRip)

0:00:01.000,0:00:04.000      1
Good morning.                00:00:01,000 --> 00:00:04,000
                             Good morning.
0:00:05.500,0:00:08.250
Two lines                    2
in one cue.                  00:00:05,500 --> 00:00:08,250
                             Two lines
                             in one cue.

Three things change:

  1. The separator between the two stamps. SBV uses a comma. SubRip uses -->.
  2. The separator before the milliseconds. SBV uses a dot. SubRip uses a comma. The two are exactly swapped, which is the detail that makes a hand edit go wrong.
  3. The cue number. SBV has none. SubRip requires a sequential number above every cue.

SBV also writes the hour without padding — 0:00:01.000 rather than 00:00:01,000.

Why Renaming Fails Silently

The tempting fix is to rename captions.sbv to captions.srt. It does not work, and the reason it catches people out is the failure mode: a player given a malformed caption file usually shows no subtitles at all, with no error message. Nothing says the file was rejected. It looks like the subtitles simply did not load, so the next hour goes into checking the player's subtitle track selector instead of the file.

Getting the File Out of YouTube

  1. Open YouTube Studio and go to Subtitles.
  2. Choose the video, then the language track.
  3. Open the three-dot menu next to the track and choose Download.
  4. Pick SBV.

YouTube offers .vtt and .srt on some tracks, and if it does, take those instead — you do not need this tool. SBV still appears often enough on older or auto-generated tracks to be worth a converter.

Converting

Paste the file's contents into the left panel, or use Upload to choose the .sbv file. The direction is detected from what you paste, and the SRT appears on the right as you type, with cue numbers added and the timings rewritten. Copy it, or download it as a .srt.

The reverse direction is there too. Switching to SRT to SBV drops the cue numbers and restores the SubViewer timings, which is what you want when uploading captions back to YouTube in the format it exported.

When a Line Will Not Convert

The error names the line number and shows the text it could not read. A single malformed timing line is the usual cause — a missing digit in the milliseconds, or a comma where the dot should be after someone edited the file by hand. Finding it is a matter of going to that line in the input panel.

What Is Preserved

Cue text, its line breaks and the order of the cues are copied exactly. Only the timing lines and the numbering change. Nothing is translated, re-wrapped or re-timed.

If you need the captions re-timed rather than reformatted, that is a different tool: the Subtitle Shifter for a constant offset, the Subtitle FPS Converter for captions that drift further out as the video plays.

What About WebVTT?

HTML5 video players want WebVTT, not SubRip. There is no direct SBV to VTT path here — convert to SRT on this page, then use SRT to VTT, which converts in both directions. Two steps, both in the browser, neither uploading anything.

Limits

  • Up to about 10 MB of text, which is far larger than any real caption file; a feature-length track is usually well under 100 KB.
  • SBV carries no styling, no positioning and no cue settings, so there is nothing of that kind to lose or to add in either direction.
  • The tool does not burn captions into video.

Privacy

The file is read in your browser with the File API and converted in the tab. Nothing is sent to a server and nothing is stored. Caption files frequently belong to unreleased video, and a format change is not a good reason for one to leave your machine — you can confirm it does not in your browser's network tab.