Are my files uploaded to a server?

No. This conversion runs inside your browser using your own device’s processing power, and the file is not uploaded. Once a tool has been used once (video, text recognition and background removal download their engine from this site the first time), it keeps working when your connection drops.

Does converting to WAV improve the sound?

No. It preserves the current audio exactly rather than recovering what MP3 compression removed. The benefit is avoiding further loss during editing.

Why is the WAV file so much bigger?

WAV stores every audio sample uncompressed: about eleven times the size of a 128 kbps MP3.

Convert MP3 to WAV

Runs on your device · Your file never leaves your device.

Convert compressed MP3 audio into WAV, the uncompressed format that audio editing and transcription software generally prefers as an input.

Converting does not restore detail that MP3 compression already discarded — it decodes what is there into a format that will not lose anything further during editing.

WAV files are substantially larger than the MP3 they came from, which is expected: nothing is being thrown away.

How to convert MP3 to WAV

Add your MP3 file.
Press Convert — the audio is decoded to uncompressed WAV.
Download the WAV, ready for editing software that will not take MP3.

Supported formats and limits

Input: MP3 audio
Output: WAV, uncompressed PCM
File size: Much larger — WAV stores every sample
Why convert: Editors, DAWs and some hardware require uncompressed audio
Where it runs: In your browser; nothing uploaded

Not for: Improving quality — WAV stops further loss but cannot restore detail the MP3 already discarded.

What the WAV file will contain

The browser’s own decoder unpacks the MP3, and the sound is written as 16-bit PCM, the plain form of WAV that editors and recorders read. A mono MP3 gives a mono WAV and a stereo MP3 a stereo one. The MP3’s tags do not come across: title, artist and cover picture are left behind, and the WAV carries sound only.

The WAV keeps the MP3’s own sample rate, read from the file’s header, so a 44.1 kHz MP3 gives a 44.1 kHz WAV with nothing resampled on the way. Only if the browser refuses to decode at that rate does it fall back to your device’s own rate, usually 48 kHz.

How big the WAV will be

A WAV’s size depends only on its length, not on how the MP3 was encoded. At 44.1 kHz, 16-bit stereo, it is about 10.6 MB per minute, roughly 635 MB per hour; at 48 kHz, about 11.5 MB per minute. So a 128 kbps MP3 grows about eleven times, and a 64 kbps one about twenty-two times.

The Downmix to mono switch averages the two channels into one and halves the WAV. When both channels carry the same sound, as in a one-microphone voice recording, nothing is lost by it.

Loud music and long recordings

Loud, heavily mastered music can decode with peaks slightly above the highest level a 16-bit WAV can hold. Those peaks are cut flat during conversion. It is rarely audible, but it is a change, not a copy.

The whole WAV is built in memory before it is saved, so the page sets a ceiling: about 56 minutes of stereo at 44.1 kHz, twice that in mono. When the part you chose is longer, the page says so before you press Convert. Switch on mono, or use the Trim slider or the Cut tab to save the recording one section at a time.

Frequently asked questions

Are my files uploaded to a server?: No. This conversion runs inside your browser using your own device’s processing power, and the file is not uploaded. Once a tool has been used once (video, text recognition and background removal download their engine from this site the first time), it keeps working when your connection drops.
Does converting to WAV improve the sound?: No. It preserves the current audio exactly rather than recovering what MP3 compression removed. The benefit is avoiding further loss during editing.
Why is the WAV file so much bigger?: WAV stores every audio sample uncompressed: about eleven times the size of a 128 kbps MP3.