OneTaskBy Tim King · Updated
MP3 to WAV Converter
Decodes in the Browser to a Plain PCM File That Opens in Any Editor
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How the MP3 To WAV works
Drop in an MP3 and download it as a plain PCM WAV. This MP3 to WAV converter decodes the file with your browser's built-in decoder and writes 16-bit or 24-bit samples, so the result opens in any editor, sampler or transcription service. Nothing leaves your device.
MP3 to WAV: lossy in, lossless container out
MP3 is a lossy codec. When the file was encoded, a psychoacoustic model removed sounds it judged you would not hear, usually most content above 16 to 19 kHz and quiet detail masked by louder sounds nearby. WAV is not a codec at all, just raw samples behind a short header. Converting MP3 to WAV therefore cannot restore what the encoder threw away, but it does freeze what is left. Every later edit, fade or re-save of the WAV is exact, whereas re-encoding an MP3 to MP3 loses a little more each generation.
What changes and what is lost
- Quality: nothing further is lost. The WAV sounds identical to the MP3 it came from.
- Size: a 128 kbps MP3 is about 0.92 MB a minute; the same audio as 16-bit stereo WAV at 44.1 kHz is about 10 MB a minute.
- Bit depth: MP3 has no fixed bit depth; the decoder outputs floating-point samples. 16-bit holds roughly 96 dB of dynamic range, more than any MP3 contains, so 24-bit is only worth it if you will process the file heavily.
- Metadata: ID3 tags and embedded cover art are not copied into the WAV.
- Padding: MP3 encoders add a few milliseconds of silence at each end. Browsers that read the LAME gapless header trim it; others leave it in.
Browser support for MP3 decoding
MP3 decodes in every current browser: Chrome, Edge, Firefox, Safari on macOS and iOS, Opera and Samsung Internet. Patents expired in 2017, so no browser leaves it out. The browser decodes at the rate its audio engine runs, usually 44.1 or 48 kHz, and the stats panel shows the rate you will get.
How to read the stats
Source is what was decoded: channels, sample rate, seconds and the original file size. Output is the WAV bit depth you have selected and Output size is the size of the export in megabytes. Switch between 16 and 24 bits to see the size change before you download.
For other sources use audio to WAV, or go back the other way with WAV to MP3. The M4A to WAV and FLAC to WAV pages cover the other common pairs.
FAQ
Does converting MP3 to WAV improve the sound quality?
No. The MP3 encoder already discarded detail and a WAV cannot bring it back. The gain is a file that every program opens and that can be edited and re-saved repeatedly without losing any more quality, which is often reason enough to convert.
Why is my WAV ten times bigger than the MP3?
WAV stores every sample uncompressed. Stereo at 44.1 kHz and 16 bits runs at about 1,411 kbps, roughly eleven times a 128 kbps MP3. The Output size line shows the exact figure for the bit depth you have chosen before you export.
Is my MP3 uploaded anywhere?
No. The file is decoded, processed and encoded inside your browser with the Web Audio API. Nothing is sent to a server, so it works offline once the page has loaded and your audio stays private.
Should I pick 16-bit or 24-bit for an MP3 source?
Pick 16-bit in almost every case. An MP3 holds less dynamic range than 16 bits can store, so 24-bit only makes the file half as large again. Choose 24-bit when the WAV is heading into heavy processing such as large gain changes or mastering.
See also: all Audio & Video tools, Units, Images, Documents, Data & Code.
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