MP4 to MP3 Converter

Extract the audio track from an MP4 video and save it as an MP3. The whole conversion runs in your browser with a WebAssembly build of FFmpeg — your video is never uploaded.

Best for

• Pulling the audio out of a lecture, interview, or podcast recording
• Saving a music or voice track from a video to listen to offline
• Getting an audio-only file that's a fraction of the video's size

Extract audio from lectures and meetings

The everyday reason to pull an MP3 out of an MP4 is that you want to listen, not watch. A recorded lecture, a team meeting, an interview, or a video podcast is often something you would rather have as audio you can play in the car, on a walk, or at double speed — and an audio-only file is a small fraction of the video's size, so it is far easier to store and share. This tool discards the video track and saves just the sound as an MP3.

Choose the right MP3 quality

The right setting depends on what you are extracting. For speech — lectures, meetings, interviews — a lower bitrate is perfectly clear and keeps the file small, because the human voice does not need much data to stay intelligible. For music or anything where fidelity matters, choose a higher bitrate: the sound is richer but the file is larger. The trade is simple — higher bitrate means better audio and a bigger file — so match it to the material rather than always maxing it out.

Does MP4 to MP3 reduce audio quality?

Extraction keeps the quality of the audio track that was already in the video — it cannot add detail that was never recorded. MP3 is a lossy format, so re-encoding drops a little data, but at a sensible bitrate that is inaudible for normal listening. What you are really doing is throwing away the video and keeping the sound, which is exactly what you want for a recording you only need to hear.

Large videos and browser performance

Because the conversion runs on your own device rather than a server, the limit is your device's memory, not an upload cap. A short clip is instant; a multi-hour recording is comfortable on a desktop but can strain an older phone. One thing to expect the first time you use any media tool here: the conversion engine (FFmpeg, compiled to WebAssembly, around 30 MB) downloads once and is then cached — so the first conversion is slower to start and every one after it begins quickly, even offline.

A note on copyright

Extract audio only from material you have the right to use — your own recordings, lectures you are permitted to keep, licensed content, or media in the public domain. Converting a file you own for your own convenience is fine; ripping audio from copyrighted video you do not have permission to reuse is not. Because everything happens on your device, this is on your honour — we cannot see what you convert, and we would rather you knew where the line is.

Private audio extraction without upload

The video never leaves your computer. The audio is extracted in your browser with FFmpeg running locally, the privacy panel shows 0 bytes uploaded, and once the engine is cached you can disconnect from the internet and it still works. That privacy is the real point for recorded meetings and lectures, which often contain things you would not want sitting on a stranger's server just to turn a video into an audio file.

What this tool does

How to convert MP4 → MP3

Frequently asked questions

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