How do I convert MP3 to WAV without uploading it?
Choose the MP3. It is decoded inside this tab and written as a 16-bit WAV at the MP3's own sample rate, then handed back as a download. The file is never sent anywhere.
MP3 to WAV
MP3 to WAV: an uncompressed copy, made in your browser
Choose an MP3 and get a 16-bit WAV of it, decoded inside this browser tab at the MP3’s own sample rate and channel count. The file never leaves your machine. The WAV is bigger and easier for an editor to open; it is not better, because what the MP3 left out stays out.
- Nothing is uploaded
- Process on your device
- Rate and channels kept
MP3 to WAV
Ready.
Why turn an MP3 into a WAV
Bigger, easier to edit, not better
Some audio editors, CD-authoring tools and upload forms want PCM rather than a compressed file, and an edit made on a WAV does not add another lossy generation until you encode again. What a WAV cannot do is bring back what the MP3 encoder discarded: the WAV plays exactly what the MP3 played, at several times the size.
| File | Size per minute | One hour |
|---|---|---|
| 192 kbps MP3 | about 1.4 MB | about 86 MB |
| The same audio as a 16-bit mono WAV, 44.1 kHz | about 5.3 MB | about 318 MB |
| The same audio as a 16-bit stereo WAV, 44.1 kHz | about 10.6 MB | about 635 MB |
Worked out from the formats themselves: a 192 kbps MP3 is 192,000 bits a second whatever is in it, and a WAV is its sample rate times two bytes per sample times its channels.
What you get
What the WAV will be
There are no settings to choose. Every MP3 is written the same way, and the result says what it wrote.
- Format
- Uncompressed 16-bit PCM WAV. There is no 24-bit or 32-bit float option.
- Sample rate
- The MP3’s own: a 44.1 kHz MP3 gives a 44.1 kHz WAV, a 48 kHz MP3 a 48 kHz WAV. Nothing is resampled, so a system that needs another rate, such as 8 kHz for a phone line, needs a different tool.
- Channels and level
- Unchanged: mono stays mono, stereo stays stereo, and no gain, normalization or noise reduction is applied.
- Length
- A WAV has to be built whole in memory before it can be handed back, so it is capped at about 400 MB: roughly 79 minutes of mono or 39 of stereo at 44.1 kHz. A longer MP3 is refused with that reason before it fails part-way.
- Files
- One at a time. To join several takes into one file, use the audio joiner; to go the other way, WAV to MP3; for M4A, AIFF and the rest, the audio converter.
Editing an audiobook chapter?
Edit the WAV, then let the checker write the MP3
ACX’s requirements ask for a 192 kbps or higher constant-bitrate MP3 at 44.1 kHz, so the WAV is a working copy, not the file you upload. Make the edit on the WAV, then hand it to the chapter checker, which measures the levels ACX measures, fixes what fails and writes the MP3 in the same step. Keep your own original master if you still have it: it is a better starting point than any MP3.
Where the file goes
Nowhere
Decoding the MP3 and writing the WAV both happen in this browser tab. The tools on this site never upload your audio, so there is nothing to delete later. The only limit is the memory ceiling above: there is no plan to upgrade and no queue to wait in.
Straight answers
Questions about MP3 to WAV
Does converting MP3 to WAV improve the quality?
No. The WAV plays exactly what the MP3 played: whatever the MP3 encoder left out stays out. What changes is that tools wanting PCM can open it, and an edit made on it adds no lossy generation until you encode again.
Why is the WAV so much bigger than the MP3?
A WAV stores every sample uncompressed. A 192 kbps MP3 is about 1.4 MB per minute; the same audio as a 16-bit stereo WAV at 44.1 kHz is about 10.6 MB per minute, and as mono about 5.3 MB.
What sample rate and bit depth does the WAV use?
16-bit PCM at the MP3's own sample rate, never resampled, with mono kept mono and stereo kept stereo. If something downstream needs a different rate, this page does not change it.
Is there a length limit?
Yes. A WAV has to be built whole in memory before it can be handed back, so it is capped at about 400 MB, roughly 79 minutes of mono or 39 of stereo at 44.1 kHz. A longer MP3 is refused with that reason before any work is wasted.