Video → MP3 Audio Extractor
Drop a video file — MP4, WebM, MOV, whatever your browser can decode — and pull the audio out as an MP3. Encoding happens locally via lamejs; nothing is uploaded.
How it works & what's supported
The video file is read into an ArrayBuffer and passed to AudioContext.decodeAudioData(), which extracts the audio track into a raw AudioBuffer. That buffer is then fed in 1152-sample chunks to lamejs, which writes MP3 frames at the bitrate you chose.
What works: any container the browser's audio decoder recognises — generally MP4/H.264 with AAC audio, WebM with Opus or Vorbis, MOV. Chrome, Edge, Firefox, and Safari each support a slightly different set; if your file fails to decode, that's the browser's decoder, not this tool. Try converting the video to WebM first.
Large files (hundreds of MB) are decoded fully into memory before encoding. Plan accordingly on mobile.