Convert WAV to MP3
Your files are processed on your device. We never upload them.
Audio is read and written with Mediabunny. MP3 files are made with LAME and FLAC files with libFLAC; browsers without their own AAC encoder use FFmpeg's. Apple Lossless files follow Apple's ALAC code.
How to convert WAV to MP3
- 01A ▸Choose a WAV file, or drop it on the page.
- 02A ▸Pick a quality. Best (320 kbps) for music you care about, High (192 kbps) for most things.
- 03A ▸Select Convert to MP3, listen to the result, and download it.
About WAV to MP3
Where WAV files come from
WAV files are uncompressed sound from recorders, audio interfaces, DAWs such as Audacity and GarageBand, and sample libraries. They take about 10 MB a minute at CD quality, which is too large for email, messaging apps, and many upload forms.
What changes
- The sound is compressed with LAME, the MP3 encoder most software uses, at the bitrate you choose. Detail you're unlikely to hear is dropped to save space.
- 24-bit and 32-bit float depth becomes MP3's own; very quiet detail below the noise floor is lost, which you won't hear at normal volume.
- Sample rates above 48 kHz are converted down, because MP3 can't hold them.
- Mono stays mono and stereo stays stereo.
Measured
Our three-minute music-like sample (stereo, 44.1 kHz, the length of a typical song), as a 16-bit WAV, converted at the High setting (192 kbps) in Chrome on a laptop. Phone timings are still to be measured.
| WAV file | 30.3 MB |
|---|---|
| MP3 file | 4.1 MB, about a seventh |
| Time in Chrome (laptop) | 1.8 seconds, including loading the MP3 encoder |
In your browser
Every browser reads WAV the same way, with the same JavaScript code inside a background worker, so 24-bit and float files decode exactly alike everywhere. No browser can write MP3 itself, so the first conversion downloads a 0.1 MB MP3 encoder (LAME); later ones reuse it from the browser's cache.
Limits
- MP3 holds at most two channels, so surround WAV files are mixed down to stereo.
- Files over 100 MB get a warning first. The conversion streams through the file rather than loading it all, so long WAVs work on phones too, just more slowly.
Other options
- WAV to FLAC (audio converter): halve the size without losing anything, for archiving.
- Increase volume: make a quiet recording louder before sharing it.
- MP3 to WAV: the other way, for editing.
Questions
How much smaller is the MP3?
A CD-quality WAV takes about 10 MB a minute. At 192 kbps the MP3 takes about 1.4 MB a minute, roughly a seventh; at 128 kbps about 1 MB, a tenth.
Are my files uploaded?
No. Your files are processed on your device. We never upload them.
Which quality should I pick?
High (192 kbps) sounds the same as the WAV to most people on most speakers. Choose Best (320 kbps) for music you'll listen to closely, and Smaller file (128 kbps) for speech, podcasts, and voice notes.
Does it work with 24-bit and 96 kHz WAV files?
Yes. 24-bit and 32-bit float WAV files convert fine. MP3 tops out at 48 kHz, so higher sample rates are converted down (96 kHz to 48 kHz, 88.2 kHz to 44.1 kHz) with a filter that keeps the sound clean.
Can I get the WAV back from the MP3?
Not exactly. MP3 throws away detail you're unlikely to hear, and it can't be restored. Keep the WAV if you'll edit the sound again.