Free converter · Lossy re-encode
Convert WAV to MP3
Short answer
Drop your WAV file into the converter below and download the MP3 file. It runs in your browser with FFmpeg, for files up to 100 MB; nothing is uploaded. The file is re-encoded to MP3 audio at about 128 kbps, keeping the source's sample rate. Re-encoding takes longer than a container swap and costs some quality; how much depends on the clip and on the quality setting, and at the converter's default setting the loss can be visible, so keep the original.
Maximum file size: 100 MB. The first conversion loads a ~30 MB converter engine, once per visit. Nothing is uploaded - conversion runs on your device.
WAV is uncompressed; MP3 is lossy by definition. · Lossy re-encode · Browser-side via FFmpeg WASM - nothing uploaded.
Key takeaways
- WAV is uncompressed (1,536 kbps for 48 kHz stereo); MP3 at this converter's 128 kbps default is 12 times smaller.
- Measured: 1,921,102 bytes became 160,749 bytes (-91.6%).
- MP3 is lossy: the saving comes from discarding audio information.
- For better quality choose -q:a 2 or -b:a 192k in a terminal; keep the WAV if you will edit it again.
Measured and computed sizes
Measured on the soundtrack of a 10 second excerpt of Big Buck Bunny (animated film; (c) Blender Foundation, CC BY 3.0), stereo, 48 kHz, using the same ffmpeg arguments this converter passes to its WebAssembly build, run with ffmpeg 6.1.1. Results describe this file.
Computed: size in bytes = bitrate in bits per second × seconds ÷ 8. A 3.5 minute (210 s) song is 3.36 MB at 128 kbps, 5.04 MB at 192 kbps, 6.72 MB at 256 kbps and 8.4 MB at 320 kbps.
| Length (stereo, 48 kHz) | WAV | MP3 128 kbps | MP3 192 kbps | MP3 320 kbps |
|---|---|---|---|---|
| 10 s (measured: WAV, MP3 128) | 1,921,102 bytes | 160,749 bytes | 240,000 bytes (computed) | 400,000 bytes (computed) |
| 3.5 min (computed) | 40.3 MB | 3.36 MB | 5.04 MB | 8.4 MB |
| 60 min (computed) | 691 MB | 57.6 MB | 86.4 MB | 144 MB |
The WAV figure follows from 192,000 bytes per second for 48 kHz 16-bit stereo.
WAV vs MP3
| WAV | MP3 | |
|---|---|---|
| Full name | Waveform Audio File Format | MPEG-1 Audio Layer III |
| What is inside | Uncompressed PCM audio | MP3 audio |
| Compression | Uncompressed | Lossy |
| Best for | Editing and mastering, where every sample matters; very large files | Music and podcasts that must play on every device |
What you get
MP3 audio at about 128 kbps, keeping the source's sample rate. WAV is uncompressed; MP3 is lossy by definition.
Pick the quality on purpose
ffmpeg -i in.wav -codec:a libmp3lame -qscale:a 2 out.mp3: VBR, 0 to 3 normally transparent per the FFmpeg wiki.ffmpeg -i in.wav -b:a 192k out.mp3: fixed bitrate.- Do not convert an MP3 back to WAV expecting the quality to return; it will only be bigger.
Keep a lossless master
WAV or FLAC keeps every sample. Make the MP3 from the master each time instead of converting a converted file.
Questions people ask
Is this WAV to MP3 converter free and private?
Yes. It is free, needs no account and runs entirely in your browser, so the file never leaves your device.
Will converting WAV to MP3 reduce quality?
Some, because MP3 is lossy and the file is re-encoded. How much depends on the clip and on the quality setting, and at the converter's default setting the loss can be visible, so keep the original. For uploads, the platform re-encodes again anyway.
Is there a file size limit?
Files up to 100 MB. The first conversion downloads a converter engine of about 30 MB once per visit; larger files are better handled by a desktop app such as HandBrake or FFmpeg.
How much smaller is an MP3 than a WAV?
About 12 times at 128 kbps: our 1.92 MB WAV became 161 KB.
Is WAV to MP3 lossy?
Yes. MP3 discards audio information to save space.
What bitrate does the converter use?
128 kbps CBR, ffmpeg's libmp3lame default.
Will I hear a difference?
It depends on the material and the bitrate. At 128 kbps differences are easier to hear than at 192 kbps or with -q:a 2.
More converters
Sources and how we checked
- MDN: Media container formats
- MDN: Web audio codec guide
- MDN: Image file type and format guide
- FFmpeg documentation: stream copy
- FFmpeg Documentation: ffmpeg (stream selection, -map, -c copy) (read 2026-10-08)
- FFmpeg Wiki: Encode/MP3 (libmp3lame quality and bitrate) (read 2026-10-08)
- Blender Foundation: Big Buck Bunny (CC BY 3.0), the clip used for the measurements (read 2026-10-08)
Reviewed October 8, 2026. What the converter writes was measured with ffprobe on the same FFmpeg build your browser downloads; format descriptions follow MDN's media guides.