01
Choose a file
Select a video or audio file from your device. It never leaves your browser.
Video to captions
Create your subtitle file
Runs on your device
Drop a video or audio file hereor click to browse · 2 GB / 2 hours technical maximum
Upload a file or paste a direct media URL to begin.
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Protected video?
Caption the video from its open browser tab.
YouTube and protected Vimeo or Zoom links cannot be imported directly. Our companion browser extension will capture the audio only after you open the video and start it yourself, then generate captions on your device. It will not bypass sign-ins, passwords, or viewing permissions.
Browser extension coming next
How it works
Captions in three simple steps
02
Generate captions
A compact Whisper model transcribes the audio locally on your computer.
03
Download or edit
Save SRT, WebVTT, or TXT captions, or correct the transcript first.
Why local processing?
Private by design. Cheap enough to stay free.
Most transcription sites upload your media to a remote server. This tool uses your browser's WebGPU or WebAssembly support instead. That protects private recordings and lets us offer the core tool without usage credits.
No uploadsYour video remains on your device.
No accountOpen the page and start working.
Reusable modelYour browser caches the AI model after the first run.
Standard formatsExport SRT, VTT, or TXT files.
Editable transcriptCorrect names and numbers before you export.
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Practical guides
Browse all guides →Make better captions, one clear step at a time.
Questions
Frequently asked questions
Are my videos uploaded?
No. Decoding and transcription happen inside your browser. We do not receive or store your media.
Why does the first transcription take longer?
Your browser must download the speech-recognition model once. It is normally cached for later visits.
Can CaptionKite summarize my video?
Not directly. CaptionKite produces an accurate, editable transcript that you can download as TXT and summarize with whichever assistant you prefer. Our guide to summarizing a video walks through the workflow, including what to correct first and what leaves your device at that point.
Which files work?
MP4, WebM, MP3, WAV, M4A, and other formats your browser can decode. The 2 GB and two-hour limits are technical ceilings; practical capacity depends on your device because transcription memory grows with audio duration. Chrome or Edge provides the best compatibility.
Can I paste a video URL?
Yes. The tool processes direct media links and authorized Vimeo or Zoom download links. YouTube, sign-in pages, and links whose owners disabled access cannot be imported yet; support for permitted playback in an open tab is planned for the companion browser extension.