Which subtitle formats does this converter support?

It reads and writes three of the most common caption formats: SubRip (.srt), WebVTT (.vtt, used by HTML5 video and most web players) and SBV (.sbv, the format YouTube exports). You can convert freely in any direction between them — SRT to VTT, VTT to SRT, SRT to SBV, and so on.

How do I fix subtitles that are out of sync?

Use the time-shift control. If captions appear too early, enter a positive offset in seconds to push them later; if they lag behind the audio, enter a negative offset to pull them earlier. The quick nudge buttons let you fine-tune in 0.1-second and 1-second steps while watching the preview table update live.

What does the framerate / speed scale option do?

Subtitles authored against a 25 fps source will drift when played over a 23.976 or 24 fps version of the same video (and vice versa). The framerate scale multiplies every timestamp by the correct ratio so the captions stay aligned for the whole runtime instead of slipping further out as the video plays.

Are my subtitle files uploaded anywhere?

No. Every step — parsing, time-shifting, format conversion and download — happens entirely inside your browser using JavaScript. Nothing is sent to a server, so even confidential or unreleased transcripts stay completely private on your own device.

What is the difference between SRT and WebVTT?

They are nearly identical: both list numbered cues with a start and end time and the caption text. The key differences are that WebVTT files begin with a WEBVTT header, use a dot before the milliseconds (00:00:01.000) instead of a comma (00:00:01,000), and support extra styling and positioning cues. This tool handles the header and punctuation differences automatically.

Can it clean up messy subtitles?

Yes. Tick Strip formatting tags to remove italic, bold and colour markup along with ASS-style override blocks, leaving plain text. Tick Fix overlapping cues to automatically trim any caption whose end time runs past the start of the next one, which prevents two lines showing at once.

Subtitle Converter (SRT, VTT, SBV)

A fast, private subtitle converter that turns SRT, WebVTT and YouTube SBV files into one another while letting you correct the timing in the same pass. It is built for anyone who has downloaded captions that play a second too early, exported the wrong format for their video player, or needs to re-sync a transcript after re-encoding a film at a different framerate. Paste the text or load a file, choose your target format, nudge the timing, and copy or download the result — all without installing software or uploading a single line to a server.

How it works

The converter first auto-detects the input format by looking for the WebVTT header, the --> timing arrow used by SRT and VTT, or the comma-separated timestamps used by SBV. It then parses every cue into a structured list of start time, end time and text, measured in milliseconds for precision. Each timestamp is read flexibly, so it copes with both comma and dot decimal separators and with or without an hours field.

Once parsed, your chosen transforms are applied in order. The time shift adds or subtracts a fixed offset from every cue. The framerate scale multiplies each timestamp by a ratio — for example 23.976 ÷ 25 when a 25 fps subtitle needs to match a 23.976 fps video — so the drift is corrected across the whole runtime, not just at the start. Optional clean-up can strip formatting tags and fix overlapping cues by trimming any caption that runs into the next. Finally the cues are re-serialised into the target format with the correct header, punctuation and numbering. A live preview table shows the first 200 cues with their adjusted timings, and a stats bar reports the cue count, character total, total span and any remaining overlaps.

Example

Suppose you have an .srt file that runs exactly 1.4 seconds ahead of the dialogue and you need a .vtt for an HTML5 <video> element. Load the file, set the output to WebVTT, type -1.4 into the time-shift box, and the preview instantly shows every caption pulled back into sync. A cue that was timed at 00:00:05,000 --> 00:00:08,000 in SubRip becomes 00:00:03.600 --> 00:00:06.600 in WebVTT, complete with the WEBVTT header. Hit Download .vtt and the corrected file is saved locally, ready to drop into your player.

Task	Input	Output	Setting
Re-sync ahead-of-time captions	SRT	SRT	shift -1.4s
Web player needs VTT	SRT	VTT	format only
Upload transcript to YouTube	VTT	SBV	format only
Match a 23.976 fps re-encode	SRT (25 fps)	SRT	scale 23.976→25

Every figure is calculated in your browser — no subtitle text is ever uploaded or stored.