Convert WAV to MP3 Online Free
Convert your .wav files to .mp3 format. Free, fast, and processed entirely in your browser — your files never leave your device.
Compress WAV to MP3 without making it sound bad
WAV-to-MP3 is the conversion most people get wrong by either over-compressing it (file sounds tinny) or under-compressing it (still too big to email). The right move depends entirely on what you're using the MP3 for. We'll walk through bitrate choices, three tools that handle the conversion, and the trade-offs nobody mentions.
When converting WAV to MP3 is the right call
- You're sending a music demo, podcast clip, or rough mix by email or chat. WAV files are 10× the size of a 320 kbps MP3, and most inboxes cap attachments at 25 MB.
- You're uploading to Spotify, SoundCloud, Apple Music, or a podcast host. They all accept WAV and re-encode it server-side anyway, so you might as well save the upload bandwidth and pre-encode at 320 kbps yourself.
- You're putting tracks on a phone, MP3 player, or older car head unit (especially USB-only stereos). MP3 is the universal format with the best storage and battery efficiency.
- You're archiving an old CD rip and want a 10× smaller library. At 256-320 kbps the difference from WAV is inaudible to most listeners on most playback chains.
- You're publishing on the open web. Browser <audio> elements play MP3 perfectly and the bandwidth cost is tolerable.
When you should NOT convert to MP3
- This is the final mix you're handing to a mastering engineer. They need uncompressed WAV — sending an MP3 forces them to work from a degraded source.
- You're going to keep editing the audio. Every MP3 encode is lossy. Re-decoding to edit and re-encoding to MP3 stacks artifacts you can hear, especially on cymbals and sibilance.
- You're archiving a master recording you can't replace. Once converted, the high-frequency detail is gone for good. Keep WAV, or use FLAC for half the size at the same quality.
- Your delivery target requires uncompressed audio (broadcast, film post, sample library distribution). Read the spec — most pro contexts demand WAV or AIFF.
How small the MP3 will be
MP3 is lossy, so file size depends entirely on the bitrate you pick. Higher bitrate means bigger file and better quality. Here's what to expect when converting a standard 16-bit / 44.1 kHz stereo WAV (CD-quality, the default):
| Duration | WAV | MP3 | Note |
|---|---|---|---|
| 1 minute | ~10.1 MB | ~2.4 MB at 320 kbps | 24% of the WAV — transparent to most ears |
| 1 minute | ~10.1 MB | ~1.4 MB at 192 kbps | 14% — good for casual listening |
| 1 minute | ~10.1 MB | ~0.96 MB at 128 kbps | 9.5% — voice / podcast acceptable, music starts to suffer |
| 10 minutes | ~101 MB | ~24 MB (320 kbps) / ~9.6 MB (128 kbps) | Comfortably under email limits at any reasonable bitrate |
Source: 16-bit / 44.1 kHz stereo WAV (~1411 kbps). All sizes assume CBR (constant bitrate) — VBR can be 5-15% smaller for similar perceived quality.
Where MP3 plays (basically everywhere)
Works with
- Every smartphone, tablet, and computer made in the last 20 years
- Every car head unit with USB or aux — even non-Bluetooth ones
- Every Bluetooth speaker, earbud, and headphone
- Spotify / Apple Music / SoundCloud / YouTube uploads (they re-encode anyway, but accept MP3 as input)
- Email attachments, Slack, WhatsApp, Discord — well under attachment limits
- CD players that read MP3 CDs (most modern ones)
Does not work with
- Mastering studios — they need WAV/AIFF for the final pass
- Sample-accurate editing — MP3 frames are 1152 samples long, edits snap to those boundaries
- Some legacy hardware samplers — MPC 2000, older Roland gear expect WAV
- Broadcast delivery (most stations spec WAV at 16/24-bit / 44.1 or 48 kHz)
How to convert WAV to MP3
Convert with WaveSieve (browser, free, no upload)
Quickest path. Conversion runs in your browser via FFmpeg.wasm — your file never leaves your device, and no account is needed. We default to 192 kbps which sounds good for almost everything.
- Drop your WAV file onto the upload area at the top of this page. Up to 100 MB per file.
- In the converter, the output is set to MP3 by default. Leave it.
- Click "Convert to MP3" — encoding takes 5-30 seconds depending on file length.
- Click "Download" to save the MP3. The original WAV is untouched.
Convert with Audacity (desktop, free, full bitrate control)
Use Audacity when you want to pick the exact bitrate (e.g. 320 kbps for archival) or use VBR. Audacity uses LAME, the gold-standard MP3 encoder.
- Open Audacity. If MP3 export prompts you for the LAME library, install it (free; the audacityteam.org instructions cover it).
- File → Open → pick your WAV.
- File → Export Audio → choose 'MP3 Files' from the format dropdown.
- In the dialog, pick a bitrate: 320 kbps (best), 256 (transparent for most), 192 (smaller). Set 'Bit Rate Mode' to Variable for ~10% smaller files at the same perceived quality.
- Click Save, fill in or skip the metadata dialog, and you're done.
Convert with FFmpeg (command line, batch, scripts)
When you have a folder of 50 WAVs to encode, FFmpeg with libmp3lame is what you want. It's the same encoder Audacity uses, just scriptable.
- Install FFmpeg: brew install ffmpeg (macOS), winget install ffmpeg (Windows), or sudo apt install ffmpeg (Linux).
- Open a terminal in the folder with your WAVs.
- Single file at 320 kbps CBR: ffmpeg -i input.wav -c:a libmp3lame -b:a 320k output.mp3
- Single file, high-quality VBR (recommended): ffmpeg -i input.wav -c:a libmp3lame -q:a 0 output.mp3 (-q:a 0 is best, 9 is worst)
- Whole folder, VBR best quality: for f in *.wav; do ffmpeg -i "$f" -c:a libmp3lame -q:a 0 "${f%.wav}.mp3"; done
Things that surprise people
Don't go below 128 kbps for music
MP3 below 128 kbps starts to introduce audible artifacts: high frequencies become smeared, cymbals turn into a watery hash, transients get a slight pre-echo. 96 kbps is acceptable for spoken-word podcasts but punishes music. If you have to go small, prefer Opus or AAC — both sound notably better at low bitrates. MP3 was designed in the 90s and modern codecs have caught up.
Don't re-encode an MP3 by going through WAV
If you're tempted to convert an existing MP3 to WAV, edit, and export back to MP3, you're stacking two lossy generations. Audible damage shows up especially on cymbals, sibilance, and electric guitar overtones. Either edit in a tool that supports MP3 directly (we do in our cleanup tool), or work from a true uncompressed source.
VBR vs CBR — VBR almost always wins
Constant Bit Rate (CBR) wastes bits on quiet passages and starves complex ones. Variable Bit Rate (VBR) adapts. For the same perceived quality, VBR gives you a smaller file. The only reason to pick CBR is if your delivery spec or older hardware demands it. Otherwise default to VBR with -q:a 0 or -q:a 2.
Frequently Asked Questions
320 kbps vs 256 vs 192 — can anyone actually tell?
On consumer earbuds in a normal listening environment, almost no one can reliably tell 192 kbps VBR from 320 kbps CBR. Studio monitors at low volume in a quiet room — yes, trained ears can spot the difference. For sharing music with friends, 192 VBR is plenty. For archival or sending to a label, default to 320 CBR or V0 VBR.
VBR or CBR for podcast / streaming uploads?
Most podcast hosts (Apple Podcasts, Spotify for Podcasters, Buzzsprout) accept either, but some podcast players hiccup on VBR seek points. Safe default for podcasts is CBR 128 kbps mono — voice doesn't need stereo, and mono halves the file. For music, VBR 0 is the best balance.
Will the ID3 tags (title, artist, album art) survive?
Yes — MP3 supports ID3 tags natively. WaveSieve doesn't write tags during conversion, but Audacity and FFmpeg can. To carry tags from a tagged WAV (BWF/RIFF tags), use Audacity's metadata dialog or FFmpeg's -map_metadata flag.
Why is my 320 kbps MP3 not exactly half the size of the WAV?
Quick math: 1 minute of 16-bit / 44.1 kHz stereo WAV is ~10.1 MB; at 320 kbps CBR an MP3 of the same duration is ~2.4 MB — about 24% of the WAV, not 50%. The 'half' intuition comes from comparing to higher-bitrate WAV (24-bit / 96 kHz). If your WAV is 24-bit, the ratio is even more dramatic.