gizmobench

MP3 to WAV Converter

Decode an MP3 and write its samples as a standard 16-bit WAV file locally. The result is larger and easier for editors to work with, but it cannot restore detail discarded by MP3.

Open a MP3 file

· or drop one anywhere on the stage

Never uploadedNo accountUp to 50 MBUp to 10 minutes
From
To
Bit depth
Sample rate
Channels
Download

Ready. Choose a MP3 file, or drop one on the stage.

The MP3 is decoded once, in this tab, after its frame header is read. The output is uncompressed 16-bit PCM at the sample rate you choose, which does not restore anything a lossy file already lost: it is a larger file, not a better one.

  • What the bytes sayread from the first bytes of the file, never from its extension
    Open a file and its container is identified before anything is decoded.
  • Output sizeexact arithmetic for PCM, an estimate for MP3
    Open a file to size the output.
  • Decoderasked of this browser before a conversion starts
    A codec with no decoder here is named up front, not halfway through.

The From control is a mode, not a guess: the first bytes of the file are read and checked against it, so a file that was renamed is refused with what it actually is. An MP4 has its audio tracks listed before anything is extracted and its video is never decoded. Changing the sample rate resamples by linear interpolation, and changing the channel count averages a stereo pair down or copies a mono channel to both sides. The ceilings are 50 MB and 10 minutes, because the whole track is held as 32-bit samples in the memory of this tab before a single output byte is written.

Converting cannot restore what a lossy file already lost. Files are decoded and re-encoded in your browser, so nothing is uploaded. Converting cannot restore detail a lossy file already lost: MP3 to WAV makes a larger file, not a better one. Which formats can be decoded depends on your browser, and this page checks the file's actual bytes and its codec before starting rather than trusting the extension.
Two open source parts do the heavy lifting, and both are served from this site. Containers are parsed and audio is decoded by Mediabunny 1.55.7 under the MPL-2.0 (licence text, the exact package, source). MP3 encoding is lamejs 1.2.7 under the LGPL-3.0 (licence text, the exact package, corresponding source). Both are bundled unmodified at those versions and loaded from this page, never from another service.

Common questions

Does MP3 to WAV improve sound quality?
No. WAV avoids another lossy encode, but it contains the samples decoded from the MP3 and cannot restore discarded detail.
Are files uploaded?
No. The file is decoded and written entirely in your browser.

Files are decoded and re-encoded in your browser, so nothing is uploaded. Converting cannot restore detail a lossy file already lost: MP3 to WAV makes a larger file, not a better one. Which formats can be decoded depends on your browser, and this page checks the file's actual bytes and its codec before starting rather than trusting the extension.