Subtitle tools that never upload your video
Clean, retime and convert your subtitle files right in the browser. Your files never leave your computer — no uploads, no accounts, no limits.
SRT Cleaner
Remove duplicate and empty cues, hearing-impaired brackets, musical notes and messy punctuation. One click, clean file.
Open the cleaner →Subtitle Shifter
Subtitles appear too early or too late? Shift every cue forward or backward by any amount of seconds and resync instantly.
Fix the timing →Subtitle Converter
Convert between SRT, WebVTT and ASS in both directions. Auto-detects the input format — just drop the file in.
Convert now →Why SubKit?
Most online subtitle converters upload your file to a server before processing it. SubKit works differently: every tool is plain JavaScript running inside your browser tab, which means your subtitles are processed 100% locally. Nothing is sent, stored or logged anywhere. It also means there is no file size limit, no queue and no waiting — a 5 MB subtitle file converts just as fast as a 5 KB one.
Which format should you use?
- SRT — the universal choice. Upload it to YouTube, load it in VLC, hand it to any video editor.
- WebVTT (.vtt) — the web standard. Required by the HTML5
<track>element; uses dots instead of commas in timestamps. - ASS — the typesetting format. Fonts, colors, positioning and effects; used by anime fansubbers and styled releases.
Coming next
A subtitle merger and splitter, a line-length fixer tuned to YouTube and Netflix guidelines, and SubKit Pro — a desktop app with AI transcription and burned-in subtitles, fully offline.