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Subtitle Generator

Generate subtitles from audio/video — AI-powered, 100% in your browser

100% free Browser-only processing Files never leave your device

Drop audio or video file here

MP3, MP4, WAV, WebM, OGG, M4A

Files processed locally — never uploaded

Also try: AI Humanizer · Summarizer · Rewriter 3 free uses/day

How It Works

1

Upload audio or video

Drop a file or click to browse. Audio is extracted automatically from video files.

2

Whisper transcribes locally

The Whisper AI model runs in your browser. No upload, complete privacy.

3

Download SRT or VTT

Review and edit the transcript, then download in SRT or VTT format.

FAQ

How does the subtitle generator work?
We use OpenAI Whisper (Base model) compiled to WebAssembly, running entirely in your browser. Your audio is transcribed locally — nothing is uploaded to any server.
What audio/video formats are supported?
MP3, MP4, WAV, WebM, OGG, M4A, FLAC, and most common audio/video formats. The tool extracts the audio track automatically.
How many languages does it support?
Whisper supports 99 languages including English, Spanish, French, German, Chinese, Japanese, Korean, Arabic, Hindi, and more. Select your language or use auto-detect.
What subtitle formats can I download?
SRT (most common, works everywhere) and VTT (WebVTT, for web video players). Both include timestamps and segmented text.
How accurate are the subtitles?
Whisper Base provides good accuracy for clear speech in supported languages. For best results, use audio with minimal background noise. Professional-grade accuracy requires the Large model (not available in-browser).
Why does the first transcription take longer?
The Whisper Base model (~57MB) downloads on first use. After that it is cached in your browser. Subsequent transcriptions start immediately.
Is my audio uploaded to a server?
No. Whisper runs entirely in your browser via WebAssembly. Your audio never leaves your device. This is our key differentiator — 100% private transcription.
How long does transcription take?
Roughly 1-3x real-time on modern devices. A 5-minute clip takes 5-15 minutes. Desktop browsers are significantly faster than mobile.
Can I edit the subtitles before downloading?
Yes. The transcribed text appears in an editable area. Fix any errors, adjust timing, then download.
Does it work on mobile?
Yes, but transcription is CPU-intensive. Short clips (under 2 minutes) work well on phones. For longer audio, use a desktop browser.
What is the file size limit?
Depends on your device memory. Audio is processed in chunks. Most devices handle files up to 100MB.
Can I transcribe a YouTube video?
Not directly. Download the video first, then upload the file. Or use our <a href="/ai/video/youtube-summarizer">YouTube Summarizer</a> for text summaries.
How does this compare to Otter.ai or Rev?
Otter and Rev use cloud-based models for higher accuracy. Our advantage: 100% free, 100% private (no upload), unlimited use. Accuracy is good for clear speech but not broadcast-grade.
Is it really free?
Yes. Completely free, no limits, no signup. Runs locally in your browser.
Can I pay with cryptocurrency?
Video tools are free. For AI writing tools, we accept USDT, USDC, BTC, ETH. Plans start at $9.99/month.

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Coda One's Subtitle Generator uses OpenAI Whisper (Base model) compiled to WebAssembly, running entirely in your browser. Transcribe audio and video into timed subtitles in 99 languages. Download as SRT or VTT. 100% private — your audio never leaves your device.

More:  All Video Tools  · Audio to Text  · Video Trimmer  · MP4 to MP3