MP4 to MP3
To convert an MP4 to MP3, choose the video, pick a bitrate (192 kbps is a great default) and press Convert. The sound is decoded and re-encoded as MP3 on your device; the video is never uploaded.
- ๐ Runs on your device
- โค 0 bytes uploaded
- ๐ด Works offline
- โ Free, no sign-up, no watermark
- โฌ 1 MB engine, first use only
How to use MP4 to MP3
- Choose or drop one or more MP4 videos.
- Pick MP3 and a bitrate, or choose M4A, WAV or "Original" to keep the sound untouched.
- Press Convert.
- Download the audio file, or all of them as a ZIP.
About MP4 to MP3
An MP4 file is a container that usually holds H.264 video and AAC audio. Converting to MP3 decodes the AAC sound and encodes it again with LAME, the reference MP3 encoder, compiled to WebAssembly and running in your browser.
MP3 plays everywhere: car stereos, old MP3 players, every phone and every computer. If you only need the sound on a modern device, "Original" is faster and loses nothing.
Is it private?
Yes. MP4 to MP3 runs entirely in your web browser using your device's own processor. Your files are never uploaded to Nolo or anyone else, and the page cannot send them anywhere: its security policy only allows it to talk to nolotools.com, which has no place to receive files. Results are kept encrypted on your device for 60 minutes in Your files, then deleted automatically, or straight away with Delete all. How Nolo works.
Questions and answers
Are my videos uploaded?
No. Everything happens inside your browser with its built-in media engine (WebCodecs). Your videos never leave your device, and the page works offline once loaded.
Which bitrate should I choose?
192 kbps sounds great for music and is the default. 128 kbps is fine for speech and podcasts and makes smaller files. 320 kbps is the MP3 maximum; it cannot add quality that was not in the video.
What does "Original (no re-encode)" do?
It copies the sound exactly as it is stored in the video, without decoding it. Most MP4s contain AAC audio, so you get an .m4a file with no quality loss, made in seconds.
Is there a file size limit?
There is no limit set by Nolo. The video is read from your disk piece by piece; only the finished audio is held in memory, so even long videos work on most devices.
Why does it say my browser cannot decode the audio?
Video and audio decoding uses your browser's WebCodecs engine, and some browsers lack certain codecs (for example AAC on some Linux builds). The latest Chrome or Edge on a computer supports the most formats.
Can I convert several videos at once?
Yes. Add as many as you like; they are converted one after another and you can download them together as a ZIP.