MP4 to MP3
MP4 to MP3 extracts the audio from a video or audio file as MP3 (128-320 kbps), lossless M4A or WAV, using Mediabunny and the LAME encoder in your browser, with no upload.
Drop a video or audio file, paste it, or click to choose one
MP4, MOV, MKV, WebM, or an audio file
Video or audio file · processed on your device, never uploaded
At a glance
- Accepts
- MP4, MOV, MKV and WebM video; M4A, AAC, MP3, WAV, FLAC, OGG and Opus audio
- Outputs
- MP3 at 128, 192 or 320 kbps; the original AAC copied into .m4a without re-encoding; or 16-bit WAV
- Where it runs
- Entirely in your browser, on your device
- What leaves your device
- Nothing - the file never leaves your device
- Limits
- MP3 and WAV need a browser that can decode the audio (Safari 26 or later on iPhone); the finished file is held in memory until saved, so very long WAVs can fail on phones; MP3 is at most stereo; Apple Lossless and DRM-protected files are not supported, and FLAC failed to decode in our Safari-engine (WebKit) test
- Account
- Not required - there is no sign-up
- Price
- Free, with no watermark and no usage cap
- Made by
- Visrut
- Last updated
- 11 October 2026
Drop in a video and get its soundtrack back as an MP3. The file is opened by your own browser: the container is read with Mediabunny, the audio is decoded with the browser's built-in decoder and encoded to MP3 with LAME, the reference open-source MP3 encoder, compiled to WebAssembly. The picture is never decoded, which is why a long video converts in seconds rather than minutes, and nothing is sent to a server at any point.
Three ways to save the audio
- MP3. The format every player, car stereo and upload form accepts. The audio is re-encoded at 128, 192 or 320 kbps, so a small amount of quality is lost, as with any MP3.
- M4A, original audio. Offered when the video's sound is AAC, which is the case for almost every MP4 and MOV from a phone or camera. The audio is copied without re-encoding: instant, and exactly the quality that was in the video.
- WAV. Uncompressed 16-bit audio for editors such as Audacity, GarageBand or a DAW. About 10 MB per minute for stereo at 44.1 kHz.
What we measured
Every format was converted in Chromium and in WebKit (Safari's engine) and checked with ffprobe. The MP3s came out at the bitrate chosen, and within 0.08 seconds of the source's length; the small extra is the MP3 encoder's own padding at the end. The M4A copies had the same number of audio packets as the source and an identical checksum.
Limits
- Files protected by DRM (purchased movies, streaming downloads) can't be read, and Apple Lossless audio isn't supported.
- FLAC audio failed to decode in our WebKit test, so on Safari it may not convert. Chrome, Edge and Firefox handled it.
- A video recorded without sound, such as many screen recordings, has nothing to extract. The tool tells you when that's the case.
How to use it
- Drop a video or audio file onto the box, or click to choose one.
- Pick MP3 and a bitrate, the lossless M4A copy, or WAV.
- Press Convert, then Download when it finishes.
If what you really need is the words, skip the MP3: Video to Text transcribes the video directly, also without uploading it.
Frequently asked questions
Is my video uploaded anywhere?
No. The file is read from your disk by your browser tab, the audio is encoded there, and the MP3 is handed straight back to you as a download. There is no server step.
Which bitrate should I pick?
128 kbps is plenty for speech: lectures, meetings, podcasts, voice notes. 192 kbps is a good default for music. 320 kbps is the highest bitrate MP3 allows; it is worth it only when the source itself is high quality, because re-encoding can't add detail that the video's audio track never had.
What is the M4A option, and why is it so fast?
Most MP4 and MOV videos store their sound as AAC. M4A is the audio-only version of the same container, so the AAC packets can be copied across untouched instead of being decoded and re-encoded. In our tests the copied audio was bit-for-bit identical to the track inside the video. It plays on iPhones, Macs, Android, Windows and in every current browser; pick MP3 only if something you use insists on .mp3.
How long can the video be?
The video track is skipped entirely, so the length of the audio is what matters. On an Apple M4 laptop, a 40-minute recording became a 192 kbps MP3 in 12 to 17 seconds in Chrome and in under a minute in WebKit, Safari's engine. The finished file is held in memory until you save it: an MP3 of a two-hour lecture at 128 kbps is about 115 MB, which phones handle, while a two-hour WAV is about 1.3 GB, which most phones won't.
Does it work on an iPhone?
Yes, on iOS 26 or later. Converting to MP3 or WAV needs the browser's built-in audio decoder (WebCodecs), which Safari added in version 26. On older iOS the lossless M4A copy still works, because it never decodes the audio.
Can I keep working in another tab?
Yes. The conversion runs in a background worker rather than on the page itself, so switching tabs doesn't pause it. Leave the tab open until the download button appears; closing it stops the job.
What about videos with 5.1 surround sound?
MP3 holds two channels at most, so surround audio is mixed down to stereo when you choose MP3. The M4A copy and WAV keep every channel.