Extract audio from video free — MP4/MOV to MP3 without uploading

Need the audio from a lecture recording, a voice memo exported as video, or a clip you shot on your phone? Desktop tools are heavy; most websites upload your whole video first.

ConvertFlow ships a full FFmpeg build compiled to WebAssembly (about 24 MB, loaded only when you convert audio/video). Your video is opened, demuxed and decoded locally, and the audio track is re-encoded to MP3 with the industry-standard LAME encoder.

Works with MP4, MOV (iPhone clips), WebM, M4A, AAC, FLAC and WAV sources. Best for clips up to ~100 MB — the conversion runs on your machine's memory, so huge files are better suited to desktop tools.

Convert MP4 to MP3 now