webUtils.uk

SRT to VTT Converter with Time Shift

HTML5 video needs WebVTT captions. Open an .srt file and download a .vtt, with the option to shift the timing at the same time. It converts VTT back to SRT as well.

How to convert SRT to VTT

  1. 1

    Open your .srt file

    Drop it on the page. The tool reads it on your device.

  2. 2

    Check the format and offset

    Save as is already set to WebVTT. Leave the offset at 0 to convert only, or enter one to fix the timing too.

  3. 3

    Download the .vtt

    The file starts with the WEBVTT header and uses the dot-millisecond timestamps browsers expect.

SRT and VTT: the differences

The two formats look almost the same, but players are strict about the details:

  • VTT files must start with the line WEBVTT.
  • VTT uses a dot before the milliseconds (00:01:04.200); SRT uses a comma (00:01:04,200).
  • Cue numbers are required in SRT and optional in VTT.
  • VTT supports position and alignment settings on each cue; they are dropped when you convert to SRT.
  • The HTML5 <track> element only accepts VTT.

Supported subtitle formats

SRT (SubRip)
The most common subtitle file. Times look like 00:01:04,200.
VTT (WebVTT)
Used by HTML5 video and most streaming players. Cue settings and styles are kept.
ASS / SSA
Styled subtitles, common for anime. Only the timings change; styles and tags stay.
SBV
YouTube’s caption format, downloadable from YouTube Studio.

Frequently asked questions

Which subtitle formats does it support?

SRT (SubRip), WebVTT (.vtt), ASS and SSA (Advanced SubStation Alpha) and SBV (YouTube captions). It can also convert any of them to SRT or WebVTT while it shifts them.

Subtitles appear too early. Do I add or subtract time?

Add time. A positive offset such as +2 makes every subtitle appear 2 seconds later. If the subtitles appear too late, subtract time with a negative offset such as −2.

How do I calculate the time offset?

Play the video and pause on a line of dialogue. Note the time the person starts speaking and the time the subtitle appears. The difference is your offset. If the subtitle appears 1.5 seconds before the voice, enter +1.5. If it appears 0.8 seconds after, enter −0.8.

Easier still: open “Match a line, frame rate and format”, type the cue number and when that line is actually spoken, and the offset is worked out for you.

Are my files uploaded to your server?

No. Your subtitle file is read and rewritten by your own browser. Nothing is uploaded, nothing is stored, and the tool keeps working if you go offline after the page has loaded.