Batch audio converter

Convert a whole folder of MP3 or WAV files in one go, then download the lot as a single ZIP. Nothing is uploaded, so a hundred files cost you nothing but time.

Batch convert MP3 to WAV

Batch convert WAV to MP3

How batch conversion works here

Most online converters queue your uploads on a server, which is why free tiers cap you at two or three files and dangle a subscription for more. Nothing is uploaded here, so there is nothing to ration.

1. Select everything at once. Ctrl+A in the file picker on Windows, Cmd+A on a Mac, or drag the files across from a folder window.
2. Set the output once. Whatever you choose in Output settings applies to every file in the queue.
3. Let it work through the list. Files convert one at a time with their own progress bar. You can remove any file mid-queue without disturbing the rest.
4. Take the ZIP. Once two files are finished, Download all as ZIP packages them in your browser and hands you one download.

Files are processed sequentially on purpose. Converting ten files in parallel would mean holding ten decoded audio buffers in memory at once, which is how browser tabs run out of room and crash. One at a time is slower to watch and far more reliable, especially on phones.

Where the limits actually are

Each input file can be up to 250 MB. The tighter constraint is usually the output: a browser tab can hold a bit under 2 GB, so the converter checks the size a WAV would reach and stops with a clear message rather than crashing halfway.

To put that in perspective, 250 MB of 320 kbps MP3 is roughly ten hours of audio, and ten hours as a 44.1 kHz 16-bit stereo WAV would be about 6 GB. That combination will not fit, and the converter says so before it starts. Splitting the recording first, or converting to mono, brings it back into range.

Phones are stricter than laptops. If a long file stops partway on mobile, either move to a desktop or pick mono and a lower sample rate.

When to use the command line instead

For hundreds of files, or anything you need to repeat exactly, ffmpeg wins. It streams audio rather than loading whole files into memory, so length stops being a constraint.

Converting every MP3 in a folder to WAV on macOS or Linux:

for f in *.mp3; do ffmpeg -i "$f" "${f%.mp3}.wav"; done

And in Windows Command Prompt:

for %f in (*.mp3) do ffmpeg -i "%f" "%~nf.wav"

Going the other way at 192 kbps:

for f in *.wav; do ffmpeg -i "$f" -codec:a libmp3lame -b:a 192k "${f%.wav}.mp3"; done

Audacity is the middle ground: import everything, then File, Export, Export Multiple. It writes one file per track and names them from the track labels.

Common questions