AnyFormat

00 MP4 → WAV

MP4 to WAV

For editing and transcription, where you want no further loss.

Drop files or a folder here

or choose from your device · paste with ⌘V / Ctrl+V

.mp4 .m4v

03Options 4

Right for speech, wrong for music. At a fixed quality the file size does not change — but mono tolerates a much lower quality than stereo, so combine the two to actually shrink the file.

Leave at 0 for the whole file.

0 means run to the end.

  • No upload The conversion runs in this tab. Your file never travels — not to us, and not to the advertising.
  • No sign-up, no email, no daily cap There is no account system to sign up to.
  • No size limit we invented Only your device's memory — about ~2 GB on a desktop browser, ~400 MB on a phone.
  • Turn your Wi-Fi off and convert anyway The conversion needs nothing but this page. Ads will not load without a connection; your file will still convert. That is the whole claim, and it takes five seconds to check.

Extracts the audio from an MP4 as uncompressed WAV. This is the right target when the audio is going into an editor, a transcription tool or an analysis pipeline — anywhere a second lossy compression would be a needless loss.

Why WAV rather than MP3 here

The MP4's audio is already lossy. Encoding it to MP3 discards a little more; writing it as WAV discards nothing further.

For listening the difference is inaudible and MP3 is a tenth the size. For processing it matters: transcription models, noise reduction, forensic analysis and mastering all work better on audio that has been through one lossy generation rather than two, and most of them want WAV as input anyway.

It will be a large file

WAV is uncompressed PCM: about 10 MB per minute in CD-quality stereo, so an hour is around 600 MB. That is the format, not the conversion.

Two things reduce it honestly. Mono halves it and is correct for speech. Dropping the sample rate to 22 kHz halves it again and is inaudible for voice. Neither adds any compression artefact, because there is no compression.

WAV cannot restore what was lost

A common misunderstanding worth stating: converting a lossy source to a lossless format does not improve it. You get a large file containing exactly the audio the MP4 had. What it does prevent is any further loss.

Formats a browser genuinely cannot read

The decoding here is the browser's own, which is fast and needs no download — and which has real gaps.

WMA (Windows Media Audio), AC-3 and DTS (cinema surround tracks), AMR (old phone voice recordings) and RealAudio are not decodable by any browser. If your file uses one you are told which, rather than being left with a failure that says nothing.

HEVC video cannot be decoded either — but that does not matter here. Extracting audio discards the video track before anything tries to decode it, so an iPhone recording converts perfectly well even though the browser could not play its picture.

Other names for this

Also searched as “extract wav from mp4”, “mp4 audio to wav”.

Questions

Why is the WAV so much bigger than the video?
WAV is uncompressed — roughly 10 MB per minute in stereo. The MP4’s audio was compressed to a fraction of that.
Does this improve the audio quality?
No. It prevents further loss but cannot recover what the source already discarded.
Which should I use for transcription?
WAV, mono, 16 kHz. That is what most speech models expect and it keeps the file small.
Is my file uploaded?
No. The demuxing, decoding and encoding all happen in this tab using the browser’s own media stack plus a WebAssembly encoder. A recording can be an interview, a lecture, a private call — none of it is transmitted. Turn your Wi-Fi off after the page loads and it still works.
How large a file can I convert?
There is no imposed limit, only your device’s memory — around 2 GB in a desktop browser and 400 MB on a phone, since the file is held in memory while it converts. A two-hour video converts in well under a minute on a laptop.
Can I convert several files at once?
Yes. Drop as many as you like, or a whole folder. Each keeps its original name with the new extension, and you can download them individually or as a ZIP.