What is the subtitle converter?
Web video players want WebVTT, most editors export SRT, and captions are forever a second or two out of sync. The GigAI Subtitle Converter fixes all three in one place.
Web video players want WebVTT, most editors export SRT, and captions are forever a second or two out of sync. The GigAI Subtitle Converter fixes all three in one place. Paste or upload an SRT or VTT file and it detects the format automatically, then converts to whichever you need, handling the small-but-annoying differences, like SRT using a comma before the milliseconds and VTT using a dot, plus the WEBVTT header and cue numbering. If the captions are out of sync with the audio, enter an offset in seconds (positive to push them later, negative to pull them earlier) and every timestamp shifts together. A clean-up option sorts the cues by start time and renumbers them. Everything runs as plain text processing in your browser, so your subtitle file, which may contain an unreleased script, is never uploaded.
- Difficulty:
- Medium
- Typical time:
- ~1–2m
- Processing:
- 100% browser processing
Last updated
How to use the subtitle converter
- 1
Paste or upload your subtitles
Drop in an .srt or .vtt file, or paste the text. The format is detected automatically.
- 2
Pick the target format
Choose WebVTT (for web players) or SRT (for editors and most media players).
- 3
Shift the timing if needed
If captions are out of sync, enter an offset in seconds, positive to delay them, negative to advance them.
- 4
Copy or download
Grab the converted, retimed file. Sort & renumber tidies everything up before you export.
What Subtitle Converter includes
SRT ↔ WebVTT both ways
Auto-detects the input format and converts to the other, handling the comma-vs-dot milliseconds, the WEBVTT header and cue numbering.
Fix out-of-sync captions
Enter an offset in seconds (positive to delay, negative to advance) and every caption shifts together so the timing lines up again.
Clean up automatically
Sort captions by start time and renumber them in one pass, tidying up files that were edited by hand.
Never uploaded
Subtitle files can contain unreleased scripts. This processes them as plain text in your browser: nothing leaves your device.
Why use our subtitle converter
Make captions work on the web
HTML5 video and most streaming players need WebVTT. Convert your SRT export in a click, ready to drop into a <track> element.
Rescue drifted subtitles
When captions run ahead of or behind the audio, a single offset re-syncs the whole file. No editing each line by hand.
Instant and free
No account, no watermark, no upload queue. Paste, adjust, download: as many files as you like.
Supported formats
Accepts SRT and VTT, and produces SRT and VTT, all processed locally in your browser.
- SRT
- VTT
- SRT
- VTT
Frequently asked questions
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Use Subtitle Converter in your code
The same engine runs behind the free API: send files, get signed download links back, and everything is deleted after the retention you choose. 1,000 tasks a month, no card.
Also runs as a task inside a job - chain it with the other engines. See the recipes.
curl -X POST https://api.gigai.tools/v1/jobs \
-H "Authorization: Bearer $GIGAI_API_KEY" \
-H "Content-Type: application/json" \
-d '{ "tasks": {
"in": { "operation": "import/url", "url": "https://example.com/input.srt" },
"work": { "operation": "convert-subtitles", "input": ["in"], "format": "srt" },
"out": { "operation": "export/url", "input": ["work"] }
} }'
# then poll until finished and follow the export URL:
curl https://api.gigai.tools/v1/jobs/JOB_ID/wait -H "Authorization: Bearer $GIGAI_API_KEY"Comparisons & guides
Go deeper on the concepts behind the subtitle converter.
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Your privacy is built in
Everything runs 100% in your browser. Your files are never uploaded to a server, never stored, and never seen by anyone but you.
- Runs in your browser
- No uploads
- Nothing stored
Ready to try the subtitle converter?
Free, private and instant. Subtitle Converter runs right in your browser.