siutil. SRT Subtitle Editor
processed in your browser · never uploaded

Subtitle (.srt)

Paste subtitles above or load a .srt file to start editing.

An online subtitle editor for .srt files that runs entirely in your browser. Without installing a desktop app, paste your subtitle text or load a file and edit the wording directly in the editor. The most useful feature is the bulk time shift: when subtitles run ahead of or behind the video, type an offset in seconds (decimals and negatives allowed) and hit Apply shift to move every start and end timecode by the same amount. Enter "-2.5" to make all subtitles 2.5 seconds earlier, or "1.2" to delay them by 1.2 seconds (any time that would go below zero is clamped to 00:00:00,000). If cues get out of order or you delete some, Renumber re-sequences them as 1, 2, 3… You can open files with the picker or by dragging and dropping onto the editor. It reads standard SRT comma timecodes (00:00:01,000) as well as VTT-style period timecodes, and always exports in the standard .srt format (commas). Because it reads both formats, you can convert too: load a .vtt and Download .srt for a VTT→SRT conversion, or load/paste an .srt and Download .vtt for an SRT→VTT conversion (.srt uses commas; .vtt uses periods with a WEBVTT header). When you're done, copy the result in one click or download it as `subtitles.srt` or `subtitles.vtt`. Your subtitle file is never sent to a server — loading, editing, time-shifting, and converting all happen on your device.

How to use

  1. Paste your subtitle text into the editor, or open a file with Load .srt or by dragging it onto the editor.
  2. Edit the wording directly. If the timing is off, type an offset (negative allowed) into Shift all by and press Apply shift. If the numbering is messy, press Renumber to re-sequence the cues.
  3. Use Copy, Download .srt, or Download .vtt to export (load a .vtt then save .srt for VTT→SRT, or the reverse for SRT→VTT). Nothing is uploaded — it all runs in your browser.

FAQ

Is my subtitle file uploaded to a server?

No. Loading, editing, time-shifting, and renumbering all run inside your browser. The .srt file is never uploaded, stored, or transmitted; it is processed only on your device, so it's safe even for subtitles of unreleased videos.

Can I fix all the timing at once when subtitles are early or late?

Yes. Type an offset into "Shift all by" and press Apply shift to move every subtitle's start and end timecode by the same amount. Use a negative number (e.g. -2.5) to make them earlier and a positive number (e.g. 1.2) to delay them; decimals are supported. Any time that would go below zero is clamped to 00:00:00,000.

What does Renumber do?

Each SRT cue starts with a sequential index (1, 2, 3…). If you delete, add, or reorder cues, those numbers can skip or repeat. Renumber re-sequences every cue from 1 in order — the old index is discarded and a fresh number is placed before each timecode line.

Can it convert between VTT (WebVTT) and SRT?

Yes, both ways. Load a .vtt (timecodes with periods, 00:00:01.000) and press Download .srt for a VTT→SRT conversion (commas, 00:00:01,000). Or load/paste an .srt and press Download .vtt for an SRT→VTT conversion — it switches the timecode commas to periods and adds a WEBVTT header. Both conversions run entirely on your device with no upload. Any VTT-specific styling you loaded stays in the editor as plain text, so tidy it up if needed.

How do I save the edited subtitles?

Use Copy to put the text on your clipboard, or Download .srt to save it as `subtitles.srt`. Saving also happens entirely on your device, with no server involved.