Needed to convert an audio file from MP3 to WAV (or the other way around) and hit sites that say "upload your file"? Your audio is personal — you can convert it entirely in your browser, without sending it to any server.
MP3 or WAV?
- MP3: small, compressed (lossy) — ideal for sharing and playback.
- WAV: uncompressed, lossless — for editing and studio work. Large file size.
Depending on your need, you'll convert one to the other: to shrink → MP3, to edit → WAV.
How does it convert in the browser?
swapfile.io decodes the audio with the browser's Web Audio engine, then re-encodes it to the target format — your file never leaves your device.
👉 WAV → MP3 converter or MP3 → WAV converter — drop your file and download it in seconds. Free, no sign-up, no upload.
An honest note
Re-encoding can't push quality beyond the source: WAV is lossless, MP3 is small and lossy. We can't add back quality the source never had — but you get a clean, fast conversion.
In short
To convert audio, don't upload your file; use the in-browser WAV↔MP3 converter to do it privately and fast. Inputs like M4A, OGG and FLAC are supported too.