Convert MP4 to MP3 Online

Convert MP4 to MP3 online with nothing to install — and, unlike other online converters, without uploading your video anywhere. The whole job runs in this browser tab.

MP4MP3

Drop your MP4 file here or click to browse

MP4 (.mp4) · Max 20 MB

Every other online MP4 to MP3 converter works the same way: you upload the video, their server extracts the audio, and you download the result. That means your file travels the internet twice, waits in a queue, and sits on hardware you don't control. This page inverts that. It loads FFmpeg compiled to WebAssembly into your browser and does the extraction on your own machine — online in the sense that there's nothing to install, local in the sense that nothing is transmitted.

The speed difference is mostly about what's missing. There's no upload (a 500 MB video on home broadband can take many minutes just to reach a server), no queue behind other users, and no download round-trip for the result. The MP3 is written straight to your disk. Extraction itself is fast because only the audio track needs decoding — the video is discarded, not processed.

Being browser-based, the same page works on Windows, macOS, Linux, ChromeOS, iPhone (Safari), and Android (Chrome). There's no version to keep updated, and none of the bundled adware that plagues downloadable 'free converter' software.

The practical use is nearly always the same: you have a video but you want the sound — a recorded lecture, a webinar, a concert clip, a screen recording with narration, a tutorial you'd rather listen to. The MP3 goes on your phone, into a podcast app, or into a playlist, and the huge video file stays behind.

One consequence of local processing worth knowing: after the page has loaded once, you can go offline entirely and the converter still works. No server-based tool can do that, and it's the simplest proof that your video isn't being sent anywhere.

Frequently Asked Questions

Is it safe to convert MP4 to MP3 online?

With most online converters your video is uploaded to their servers, so it depends on their retention policy. With this one the question doesn't arise: extraction happens in your browser and the file is never transmitted. You can even disconnect from the internet after the page loads and it still converts.

How long does an online MP4 to MP3 conversion take?

Seconds for typical files, because there's no upload or download round-trip and only the audio track is decoded. Large videos are limited by your device's speed, not by a server queue.

Is there a file size limit?

The free tier accepts videos up to 20 MB with a 10-second output preview; Pro raises the input limit to 500 MB and gives full-length audio. Since processing is local, there's no server-side cap beyond your own device's memory.

Does it work on a phone browser?

Yes — Safari on iOS 15.4+ and Chrome on Android run the extraction fully, so you can pull the audio out of a video without moving it to a computer first.

Do I need to install anything?

No. It's a web page. There's no software, no extension, and no ffmpeg command line to learn — the FFmpeg engine ships to your browser as WebAssembly when the page loads.