01Subtitle source
UTF-8 · SRT, VTT, or SBV · up to 5 MB
Captions that stay with you
Convert, check, and shift subtitles.
Keep every caption local.
Move between SRT, WebVTT, and SBV, inspect timing problems, edit cues, and preview against a local video without uploading either file.
⌁Local-only filesCCSRT · VTT · SBV±Millisecond timing
THE SUBTITLE WORKSPACE
Paste captions. Check the timing. Export cleanly.
Private by defaultCaption and video bytes stay in this tab.
02Converted output
Timing and text checks
✓ No cue issues found.
03
Cue editor
0 cuesConverted captions will appear here.
04
Local video preview
Load an optional browser-playable video and preview the current cues as captions.
Video stays on this device · up to 1 GBWHY THIS TOOL
A complete caption handoff in one private tab.
One cue model
SRT, WebVTT, and SBV normalize to exact milliseconds, so conversion stays predictable.
Warnings, not guesses
Overlaps, empty text, ordering, and invalid durations are surfaced without silently rewriting timing.
Preview without upload
A temporary WebVTT track is attached to your local video and released when you clear the workspace.
QUICK ANSWERS
Format changes without a cloud detour.
Which subtitle formats are supported?
The toolkit reads and writes basic SRT, WebVTT, and SBV subtitle files in UTF-8.
Does validation automatically change timing?
No. It reports overlaps, ordering, empty text, and non-positive durations. Only an exact shift you request changes cue times.
Are my captions or video uploaded?
No. Parsing, editing, preview, and export happen inside this browser tab.
THE TOOLKIT
More one-minute tools, same boundary.
LocalConvert is growing into focused one-minute tools for documents, creators, developers, and small teams.