MP4 to MP3 Online

MP4 to MP3 is a free online tool that extract audio from video files and save as MP3, entirely in your browser. No files are uploaded — everything is processed locally on your device.

MP4 to MP3 conversion extracts the audio track from an MP4 video file and re-encodes it as a standalone MP3 audio file — typically reducing file size by 80–95%, since the video stream usually accounts for 90%+ of an MP4's bytes. A 10-minute 1080p MP4 (~200 MB) becomes a roughly 10–24 MB MP3 depending on bitrate. MP4 is defined in ISO/IEC 14496-14; MP3 is defined in ISO/IEC 11172-3. This audio extractor is commonly used to rip music from video recordings, create podcast episodes from video interviews, save lecture audio for offline listening, or extract background music. The tool strips out the video stream and re-encodes the audio at your chosen bitrate: 128 kbps is transparent to ~95% of listeners for speech content, 192 kbps is the balanced default for mixed content, and 320 kbps preserves audiophile-grade quality for music. Powered by FFmpeg WebAssembly, the entire conversion runs locally in your browser — your video files are never uploaded to any server, making it safe for private lectures, confidential meetings, and any copyrighted content.

Privacy guarantee: MP4 to MP3 processes all files directly in your browser using WebAssembly. No data is uploaded to any server, no information is collected, and the tool works offline after loading. Unlimited usage with no signup, no watermarks, and no file size limits.