Auto Caption Generator
Generate captions for any video with AI, automatically. Produces SRT/VTT subtitle files and can burn captions into the video, all locally in your browser.
Drag & drop files here
or
Choose filesProcessed on your device. Nothing is uploaded
How to Auto Caption Generator
- 01Add your files
Click “Choose Files” or drag and drop them onto the page. Batch conversion is supported.
- 02Adjust settings
Pick quality, size or other options. Sensible defaults are pre-selected.
- 03Convert & download
Hit Convert and download your files. Everything runs locally. Nothing is uploaded.
Frequently asked questions
How do auto captions work?
The audio is extracted from your video with an in-browser FFmpeg, then transcribed by the Whisper AI model with word-level timing, producing ready-to-use caption files. Nothing leaves your device.
What do I download?
An SRT subtitle file (accepted by YouTube, VLC, Premiere and every major player). Enable burn-in to also get a copy of the video with captions rendered on top.
Is there a length limit?
No fixed limit. Longer videos simply take longer, since your own device does the AI work. Shorts and clips of a few minutes finish fastest.