MP4 to SRT Converter
Generate a new subtitle file from the speech in your MP4. Your video stays on your device throughout processing.
AI model will be downloaded once and cached in your browser. Download size depends on the model and backend; actual size appears during download.
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How it works
- Choose an MP4 file containing speech.
- Run local Whisper transcription.
- Edit the result and save an SRT file.
Key features
- MP4 to SRT converter powered by local speech recognition.
- Tiny and Base Whisper model choices.
- No account, media upload or paid API.
Supported formats
MP4 with browser-decodable audio, commonly AAC. Up to 30 minutes per file.
Private by design
Your files stay on your device. Media is processed locally and is not uploaded to our server. Whisper runs in your browser; model downloads come from model hosting or a CDN.
Frequently asked questions
Does this extract an existing subtitle track?
This tool generates new captions from audio. Use Extract Subtitles from MP4 for existing embedded text tracks.
Why does my MP4 fail to decode?
MP4 is a container and can include different audio codecs. Your browser must support the codec in the file.
Can I remove burned-in subtitles?
No. This tool transcribes audio and does not remove text from video frames.