How to use it· 4 steps
- Drop your MP3 file into the box above, or click it to choose one.
- Leave “Convert to” on WAV; set the sample rate and channels only if your destination asks for specific values.
- Press Convert audio. The first conversion downloads a 32 MB engine; after that it starts at once.
- Listen to the result on the page, then press Download to save the WAV.
Step by step
How to use the mp3 to wav converter
- 1Drop your MP3 file into the box above, or click it to choose one.
- 2Leave “Convert to” on WAV; set the sample rate and channels only if your destination asks for specific values.
- 3Press Convert audio. The first conversion downloads a 32 MB engine; after that it starts at once.
- 4Listen to the result on the page, then press Download to save the WAV.
What is inside an MP3 file
MP3 — MPEG-1 Audio Layer III, developed largely at Fraunhofer IIS and standardised in 1993 — is compressed, lossy audio. Turning it into WAV does not undo that compression. It decodes the MP3 into plain PCM samples and writes them out uncompressed, which is exactly what some software needs to work with sound, but the result contains only what the MP3 kept.
Expect the file to grow roughly sevenfold to tenfold. A 4-minute song at 192 kbps is about 5.8 MB as MP3 and about 42 MB as 16-bit 44.1 kHz stereo WAV.
Why convert MP3 to WAV?
MP3 files usually arrive as one of three things: a music file that an editor, DJ tool or video app wants as WAV; a recording that has to go onto an audio CD, which needs 16-bit 44.1 kHz stereo PCM; or an announcement or prompt for a phone system, which often asks for WAV.
Audio editors and some DAWs work in PCM, and editing a decoded WAV avoids re-encoding the MP3 at every save.
Phone systems, alarm panels and voice-prompt hardware frequently accept only WAV — often 8 kHz mono for telephony.
Burning an audio CD, sampling into music software, or feeding a speech-recognition system that wants PCM.
What happens to the sound
Decoding to WAV loses nothing further: the WAV holds the MP3's sound exactly. But it gains nothing either. The detail removed when the MP3 was made is gone, so a 128 kbps MP3 becomes a large WAV that still sounds like a 128 kbps MP3.
The useful property of the WAV is what happens next. Editing and saving an MP3 repeatedly re-encodes it each time, piling up artefacts. Edit the WAV, and you encode once at the very end.
Size goes the other way here. About 1–2.4 MB per minute as MP3; as 16-bit stereo WAV at 44.1 kHz it is about 10.6 MB per minute (1,411 kbps), and half that in mono. A one-hour recording is roughly 635 MB as stereo WAV.
Settings that suit an MP3 source
For editing or a CD: keep the sample rate at 44.1 kHz and Stereo. That is CD audio exactly.
For telephone systems: check the required format first. Many want mono 16-bit PCM — choose Mono — at a low sample rate. This converter offers 48, 44.1 and 22.05 kHz; if the system insists on 8 kHz, run the WAV through the system's own import tool, which will resample it.
WAV has only basic tag support, so title and artist from the MP3's ID3 tag are kept where ffmpeg can map them; cover art is dropped.
Problems you may run into with MP3
The WAV is huge — that is normal — WAV is uncompressed. About 10 MB per minute in stereo at 44.1 kHz; choosing Mono halves it.
There is a short silence at the start — MP3 encoders add a few dozen milliseconds of padding. ffmpeg trims it when the MP3 carries a LAME gapless header; MP3s without one keep it.
The phone system rejects the WAV — telephony systems often want 8 kHz mono, sometimes µ-law or A-law encoded. This tool writes 16-bit PCM; if µ-law is mandatory, convert the WAV with the system's own utility.
Your MP3 stays on your device
Recordings are often the most private files people own — interviews, voice notes, meetings — and the usual online converter starts by uploading them.
This converter brings the conversion to the file instead. ffmpeg, compiled to WebAssembly, runs in the tab; the MP3 is read locally and the WAV is produced on your device.
The one network cost is the engine itself, about 32 MB, downloaded once the first time you convert and reused for the rest of the session. After that you can disconnect and convert offline.
Answers
Frequently asked questions
Does MP3 to WAV improve quality?
No. The WAV is a perfect copy of the decoded MP3, so it sounds identical — just in a much larger, uncompressed file.
Why convert MP3 to WAV at all?
Software and hardware that needs uncompressed PCM: audio CDs, phone systems, samplers and some editors. Editing a WAV also avoids stacking MP3 re-encodes.
What WAV format does this produce?
16-bit PCM, little-endian — the standard, universally readable kind — at the MP3's sample rate unless you choose another.
Are my MP3 files uploaded?
No. The conversion runs in your browser with a WebAssembly build of ffmpeg; the file is read from your disk and the WAV is created on your device.
Why is there a pause before converting begins?
On first use the browser fetches the 32 MB conversion engine. It stays loaded while the tab is open, so the next file starts straight away.