Subtitle Tools

How to use this tool

1. Drop in an .srt or .vtt file, or paste the subtitle text directly into the input box.
2. Pick the format you want out — WebVTT for HTML5 video, SubRip for almost everything else.
3. If the timing is off, use "Shift timing" for a constant offset, or "Frame-rate fix" for subtitles that drift progressively out of sync.
4. Check the live output preview, then download the converted file.

Common mistakes to avoid

• Don't use the shift control to fix drift. If subtitles are correct at the start of a video but progressively wrong later, no single offset will fix it — you need the frame-rate correction instead.
• Don't rename a .srt to .vtt and expect HTML5 video to accept it. WebVTT requires the WEBVTT header line and period-separated timestamps; renaming alone produces a file the browser silently refuses to display.

Fixed offset vs. progressive drift

Almost every out-of-sync subtitle problem is one of two things, and they need different fixes. A fixed offset means the subtitles are wrong by the same amount everywhere — three seconds early at the start, three seconds early at the end. This usually comes from a different release of the same video with a slightly longer intro, and a single shift corrects it.

Progressive drift means the error grows as the video plays — nearly perfect at the start, badly wrong by the end. This is a frame-rate mismatch: the subtitle file was timed against a version of the video running at a different frame rate, so every timestamp is off by a constantratio rather than a constant amount. Correcting it requires multiplying all timings by that ratio, which is what the frame-rate presets do. The classic pairing is 25fps (PAL) against 23.976fps (film), which drifts by about 4% — roughly two and a half minutes over a feature film.

Frequently asked questions

What is the difference between SRT and VTT?

They are nearly the same format. SubRip (.srt) is the older and most widely supported, using a comma as the decimal separator in timestamps (00:00:01,000). WebVTT (.vtt) is the format HTML5 video requires for the <track> element, uses a period instead (00:00:01.000), and begins with a WEBVTT header line. Converting between them is mostly a matter of rewriting the timestamps.

My subtitles start in sync but drift further out of sync as the video plays. How do I fix that?

That is a frame-rate mismatch, not a timing offset — the subtitle file was authored against a different frame rate than your video, so the error accumulates. Use the frame-rate fix rather than the shift control: shifting moves every cue by the same fixed amount, which cannot correct a drift that grows over time. The most common case is a 25fps subtitle file against 23.976fps video.

My subtitles are consistently a few seconds early or late. How do I fix that?

That is a fixed offset — use the shift control. Enter a positive number of seconds to move subtitles later, or a negative number to move them earlier. The preview updates as you type, so you can check the first cue against where the dialogue actually starts.

Will my cue numbering and formatting be preserved?

Cues are renumbered sequentially from 1 on output, which quietly repairs the gaps, duplicates, and missing numbers that real-world subtitle files often contain. The text of each cue, including line breaks and inline tags, is passed through unchanged.

Is my subtitle file uploaded anywhere?

No. The file is read and rewritten entirely in your browser. This matters for anything unreleased or confidential — subtitle files for unpublished video routinely contain the full script.

How GetByteRush compares

Most free tools for this online work the same way: you upload your file to their server, wait, then download the result — which means your file (and often your email, for a "free" account) sits on someone else's infrastructure. Here's the actual difference:

("Typical online tools" reflects publicly documented behavior of common free file-processing sites as of 2026 — always check a specific competitor's own privacy policy and pricing page, since these details change.)