Can I convert SRT to VTT?
Yes — that's the core of the API. POST /api/v1/convert with from=srt, to=vtt. VTT to SRT works the same way.
Do you support ASS?
Yes. ASS is a supported input and output, so you can convert SRT/VTT → ASS and back, including positioning via the position parameter.
How do I automate this in CI/CD?
The endpoint is a plain HTTP POST. Drop a curl call (or your language's fetch/requests equivalent) into a pipeline step. With a stored subtitle API key and credits, you can convert subtitles on every build.
What happens when credits run out?
Conversions stop and return 402 insufficient_credits. Your account and key stay intact — top up via Checkout and you're back up immediately.
Is this free?
Every new key starts with 100 free credits — enough to test the full API, including cleanup and resync. Beyond that it's pay-as-you-go from $2 for 1,000 credits, with no subscription.
How is this different from ffmpeg?
No binary to install, no encoding flags to master, no version drift. This is a hosted subtitle conversion API: send a file, get a clean, correctly formatted file back — with dedupe, SDH cleaning, casing fixes, and resync as first-class parameters.
Do you burn subtitles into video?
No. SubtoVTT converts and cleans subtitle text — it does not render or burn captions into video frames. If you need burned-in subtitles, pair this API's output with your existing encoder.
Get started
Get your free API key → subtitle API pricing & signup — 100 free credits, no subscription.
Try the free SRT to VTT converter → free online converter.
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