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Convert MP4 to MP3 online

Extract the audio from an MP4 video and download it as MP3, processed entirely in your browser — the file is never uploaded to a server.

Processed on your device via WebAssembly. Nothing is sent to any server.

or click to select it

Convert an MP4 video into an MP3 audio file without installing any software or uploading the file to a server — the whole process happens in your own browser.

Strips the video portion and keeps only the audio from the MP4 file, encoding it as MP3, a compressed audio format supported by virtually every player.

Use cases

  • Extract the music from a video to listen to offline.
  • Save the audio from a recording or interview in a lightweight format.
  • Convert downloaded videos to MP3 to play on a device that doesn't support video.

How it works

  1. 1

    Upload your MP4 video

    Drop the file in or select it from your device.

  2. 2

    Click Convert

    ffmpeg.wasm extracts the audio track directly in your browser.

  3. 3

    Download the MP3

    Once it's done, download the resulting audio file.

Technical details

Uses ffmpeg.wasm, a WebAssembly build of FFmpeg running inside a Web Worker in your browser. The first conversion downloads the engine (around 7 MB); later conversions in the same session are faster since it's already loaded. On lower-powered devices the process may take a bit longer.

Frequently asked questions

Does converting lose quality?

The resulting MP3 uses a high encoding quality, good enough for most uses; since it's lossy compression, it isn't an exact copy of the original audio.

Is there a file size limit?

Videos up to 300 MB work reliably on most devices; larger files may exhaust the browser's available memory.

Video & Audio