MP4 to MP3 converter

MP4 is a container: one file holds the picture (usually H.264 or HEVC) and the sound (almost always AAC). Converting MP4 to MP3 throws away the picture, decodes the audio track and encodes it as MP3. You end up with a much smaller audio file that plays on any player, car stereo, old MP3 player or phone.

This tool decodes the audio with your browser's built-in decoder, and a LAME encoder running in JavaScript writes the MP3. So the video is never uploaded: everything happens on your own computer or phone. That makes it safe for a confidential talk, a family video or a recording of a work meeting.

MP3 quality comes down to bitrate: the higher it is, the more detail survives and the bigger the file.

Worth knowing: the AAC audio inside a video is already compressed. If the source is 128 kbps AAC (true for many phones and most social media videos), a 320 kbps MP3 won't sound any better – it will only be larger. For speech, 128 kbps is plenty; for music, 192 kbps is the sweet spot.

• Lectures, webinars, classes: turn a recorded video into audio you can listen to on the go.
• Music from your own videos: keep the sound of a concert clip or your own playing as a separate file.
• Interviews and podcasts: if you recorded a conversation over a video call, an MP3 is easier to edit, transcribe and share.
• Voice messages: forward a message someone recorded as a video as plain audio.
• Older devices: plenty of car stereos, speakers and MP3 players only understand MP3, not M4A or AAC.

Only convert audio you have the right to use: your own recordings, openly licensed material, or content you have permission for.

“Your browser couldn't decode the audio.” Occasionally an MP4's audio isn't AAC but AC-3 or E-AC-3 (surround sound from movies), which browsers can't decode. Try Chrome or Edge; if that fails too, this file's audio can't be processed in a browser.

The video has no audio. Some screen recordings and edited clips are silent. The tool tells you so instead of producing an empty MP3.

A very large file. To decode the audio, the browser reads the whole file, so a multi-gigabyte movie can run a phone out of memory. That's rarely an issue on a computer; if it is, shorten the video first with the video trimmer.

MP4 is video (picture + sound), M4A is the same container without the picture (AAC audio), and MP3 is an older audio format that plays absolutely everywhere. At the same bitrate AAC sounds slightly better than MP3, but MP3 wins on compatibility: every device and program supports it.

If your video isn't MP4 but MOV, WebM or 3GP, use video to MP3; for iPhone MOV clips there's also MOV to MP3. If you want lossless audio for editing or mixing, MP4 to WAV is the better choice.

• Recording too quiet? Run the MP3 through the volume booster to bring it to the −16 LUFS podcast standard or −14 LUFS for music, without clipping.
• Too long? If there's dead air at the start or end, cut it in the MP3 cutter – the file gets smaller too.
• For speech, 128 kbps is more than enough; with a mono source you won't hear a difference against 192 kbps.
• Transcripts: if you want text from the speech, MP3 works with nearly every transcription tool.
• File names: the downloaded MP3 keeps the video's name, so it's easy to keep track of several files.

The conversion runs entirely in your browser. Your file isn't uploaded, stored or seen by us. Close the tab and the processed data is gone from memory too. That's also why there's no file size or file count limit imposed by a server – only your device's memory matters.