ALL AUDIO TOOLS18
WAV to MP3
Convert WAV to MP3 Online — Free & Adjustable Bitrate
Compress WAV files to MP3 with selectable bitrate — 128, 192, 256, or 320 kbps.
Nothing is enforced, but the whole WAV is held in memory while it is decoded to 32-bit float — twice what 16-bit samples take on disk — so a multi-hour master needs several times its own size in RAM before the MP3 encode starts.
About WAV to MP3
WAV files are uncompressed and can be very large — a 3-minute song at CD quality (44.1 kHz, 16-bit stereo) is roughly 30 MB. This makes WAV impractical for sharing via email, messaging apps, or web uploads. Converting to MP3 can reduce the file size by 80-90% while retaining good listening quality that most people cannot distinguish from the original. This tool uses the lamejs MP3 encoder running entirely in your browser via JavaScript — no server uploads, no plugins, and no software to install. Choose your preferred bitrate to match your needs: 128 kbps for spoken word and small file sizes, 192 kbps for a good balance between quality and size, and 256-320 kbps for near-transparent quality suitable for music. Common use cases include converting voice recordings for email sharing, compressing podcast recordings for distribution, preparing music files for portable devices with limited storage, and reducing the size of audio assets for web applications.
Questions
What bitrate should I choose?
128 kbps is fine for speech and podcasts. 192 kbps is a good balance for music. 256-320 kbps is nearly indistinguishable from the original for most listeners.
How much smaller will the MP3 be?
Typically 80-90% smaller. A 30 MB WAV file at 192 kbps becomes about 4 MB as MP3.
Is there any quality loss?
Yes, MP3 is a lossy format — it discards audio data that's less perceptible to human hearing. At 192 kbps or higher, the difference is very hard to notice for most listeners.
What happens to a 96 kHz or 192 kHz WAV?
MP3 can't carry sample rates above 48 kHz, so anything higher is resampled down to 48 kHz before encoding. Files at 44.1 or 48 kHz keep their original rate untouched.
Can I convert a surround (5.1) WAV?
Yes, but MP3 holds at most two channels, so anything wider is folded down to stereo with the extra channels mixed in at -3 dB — which keeps the center-channel dialogue instead of dropping it. Mono and stereo files pass through with no channel changes.
Is my file uploaded to a server?
No. Transmute processes everything locally in your browser using JavaScript and WebAssembly. Your files never leave your device — there is no server, no upload, no cloud processing.