Why convert MP3 to WAV
Audio editors, DJ software, phone systems, game engines and some transcription tools ask for WAV. Converting gives them plain, uncompressed PCM that every program reads.
MP3 is MP3, the audio format every player, car stereo and phone plays; WAV is WAV, uncompressed audio straight from recorders and editing software.
What changes
- WAV stores the decoded sound as 16-bit PCM, so the file is about ten times larger than the MP3; the quality is the MP3's, not better.
- Sample rate and channels are kept (mono stays mono, stereo stays stereo).
On your device
Your files are converted by your browser and never uploaded, so there is no sign-up, no file-size cap beyond your free disk space and no daily limit. You can convert up to five files at once.
How this works
The file is read in slices by Mediabunny in a Web Worker, which finds the audio track; your browser's built-in decoders (WebCodecs) turn it into sound samples, which are then written as 16-bit PCM in a WAV file. The result is written to the browser's private storage as it is produced, so long recordings don't need to fit in memory, then offered for download. Nothing is uploaded.
Frequently asked
Does WAV improve the quality?
No. The MP3's sound is stored uncompressed, which makes editing easier but can't restore what MP3 compression removed.
Are my files uploaded?
No. The conversion runs in your browser on this device; nothing is sent to a server.
Is there a size limit?
Only your device's free disk space. Long recordings are written to the browser's private storage as they are converted.
Sources
- ISO/IEC 11172-3 — MPEG-1 Audio (including Layer III, MP3)
- Library of Congress — WAVE Audio File Format (format description)
- Mediabunny documentation — Converting media files
Reviewed Oct 19, 2026 · test vectors fixtures/convert/audio/mp3-to-wav/