AI subtitle generator
Generate accurate SRT and VTT subtitles from any video or audio file with this free AI subtitle generator. Runs in your browser, no upload, no sign-up.
100% private — files never leave your deviceYour browser can’t run this tool. Please try the latest Chrome, Edge or Safari on a desktop.
Loading the AI model (first time only)…
The AI model downloads once, then runs entirely on your device — this can take a few seconds on the first run. It’s cached afterwards, so next time is instant.
How to use
- Add your media. Drop in a video or audio file, or click to browse and select one from your device.
- Let the model load. On the first run the Whisper model downloads once (75MB+) and is cached for future offline use.
- Transcribe the speech. Start transcription and let Whisper detect speech and generate timestamped caption lines locally.
- Download SRT or VTT. Export your subtitles as a .srt or .vtt file ready to attach to a player or video editor.
Features
- Runs fully in your browser. Whisper executes locally via transformers.js, so your audio and video are never uploaded to a server.
- SRT and VTT output. Export captions in the two most widely supported formats for editors, players, and the web.
- Works offline after first load. Once the model is cached, you can generate subtitles without an internet connection.
- No sign-up, no watermark. It's free to use with no account, no limits per file, and nothing stamped on your captions.
- Accurate timestamps. Whisper produces time-aligned caption lines so subtitles stay in sync with the speech.
When to use it
- Add captions to a YouTube or social video before uploading it
- Create an SRT file for a podcast or interview recording
- Generate VTT captions for embedding video on a website
- Make accessible subtitles for lectures, webinars, or training clips
- Get a rough transcript with timestamps you can clean up in a video editor
Is it private?
Your video and audio are transcribed entirely in your browser with no upload, so your files never leave your device.
Frequently asked questions
Is this AI subtitle generator free?
Yes. It's completely free with no sign-up, no per-file limits, and no watermark on your subtitles.
Are my files uploaded anywhere?
No. The Whisper model runs entirely in your browser, so your video and audio are processed locally and never sent to a server.
What file formats can I use, and what do I get back?
You can feed in common video and audio files, and you can download the generated subtitles as .srt or .vtt files.
Why does the first run take longer?
The first time you use it, the Whisper model (75MB+) downloads once. After that it's cached in your browser and loads quickly, even offline.
How long does transcription take?
It depends on your device and the file length. Short clips are quick, but long recordings can take several minutes since all the work happens on your own hardware.
How accurate are the subtitles?
Whisper is strong on clear speech, but expect occasional errors with heavy accents, background noise, crosstalk, or technical terms. Review and tidy up the output before publishing.
Will it work on my phone?
It can, but speech recognition is memory-intensive. Very large files may be slow or fail on low-memory phones, so a laptop or desktop is more reliable for long media.
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