WAV to MP3 converter
Choose WAV files, pick an MP3 quality and download much smaller MP3s. It runs in your browser and nothing is uploaded.
Free · no signup Runs in your browser
How do I convert WAV to MP3?
Choose the WAV files, pick a quality and download the MP3 versions. A WAV file stores sound uncompressed, so CD-quality audio takes about 10.6 MB a minute. An MP3 at 192 kbit/s takes about 1.4 MB a minute, roughly one-seventh of the size. The conversion happens in your browser and the files are never uploaded.
Why shrink a WAV
WAV is the format of choice for recording and editing because it keeps every sample exactly. CD-quality sound is 44,100 samples a second, each 16 bits, in two channels, which is 176,400 bytes every second, or about 10.6 MB for each minute. That is too big to email, slow to upload and heavy on a phone.
MP3 compresses the sound by leaving out detail the ear is least likely to notice. At 192 kbit/s a minute of stereo sound is about 1.4 MB, roughly one-seventh of the WAV, and for most listening the difference is hard to hear. For speech, 128 kbit/s in mono is smaller still: about 0.5 MB a minute. Keep the WAV if you will edit the sound further, because every MP3 save loses a little more.
It runs in your browser. Your files are never uploaded, and there is no watermark or sign-up. MP3 encoding uses LAME (lame.sourceforge.io), an open-source encoder, licensed under the LGPL.
How it works in detail
The WAV is read on your device and decoded to samples by your browser, and the samples are encoded as MP3 with LAME at the bit rate you choose: 128, 192, 256 or 320 kbit/s. CD-quality WAV is 44,100 samples a second × 2 bytes × 2 channels = 176,400 bytes a second, while MP3 size is the bit rate ÷ 8 × seconds, so at 192 kbit/s it is 24,000 bytes a second, which is 13.6% of the WAV. 'Make it mono' halves the data again by joining the channels. MP3 is lossy, so some detail is discarded to make the file smaller; at 192 kbit/s or above most people cannot hear the difference in everyday listening. Several files can be converted at once.
How to use it
- Choose one or more WAV files.
- Pick the MP3 quality: 128 for small files, 192 for a good balance, 256 or 320 for high quality.
- Tick 'Make it mono' for speech or to save more space.
- Wait for the conversion; each file shows its new size.
- Download each MP3 or all of them.
What changes and what stays the same
What the tool does to your file, and what it leaves alone.
| Aspect | What happens |
|---|---|
| File size | About 13.6% of the WAV at 192 kbit/s |
| MP3 quality | MP3 is lossy: each save as MP3 costs a little detail, so keep your original |
| Length | The same as the WAV |
| Channels | Stereo, or mono if you choose |
| Tags | Not copied |
| Privacy | Your file is read on your device and is not uploaded; there is no account and no watermark |
When to use it
- Sending a recording by email or message
- Putting recordings on a phone or MP3 player
- Uploading to a site that does not accept WAV
- Saving space on a drive
Problems you may run into
Most problems come from the file itself, not from the tool.
| What you see | Likely cause | What to do |
|---|---|---|
| The MP3 sounds worse than the WAV | A low bit rate discards more | Choose 256 or 320 kbit/s |
| The files are still big | High bit rate or long recordings | Use 128 kbit/s, or mono for speech |
| I need to edit later | Each MP3 save loses a little | Keep the WAV as your master |
| A gap appears between tracks | MP3 adds a short padding at the ends | Use WAV or a gapless format for albums |
| The file will not open | Your browser cannot decode this format, or the file is damaged | Try Chrome, Edge or Firefox on a computer, or open the file elsewhere to check that it plays |
| The browser slows down or stops | A very large file is processed on your own device | Close other tabs, try a computer, or use a smaller file |
Mistakes it helps you avoid
- Deleting the WAV before you are sure you will not edit it again.
- Choosing too low a bit rate for music.
- Converting an MP3 to WAV and back, which adds loss without adding quality.
- Using stereo for a mono recording: it doubles the size for nothing.
How it works
Your file is decoded and re-encoded inside your browser.
1. The WAV is read on your device and decoded to samples by your browser.2. The samples are encoded as MP3 with LAME at the bit rate you choose.3. The MP3 is offered as a download. Nothing is uploaded.
CD-quality WAV is 44,100 samples a second × 2 bytes × 2 channels = 176,400 bytes a second. MP3 size is bit rate ÷ 8 × seconds. At 192 kbit/s that is 24,000 bytes a second, which is 13.6% of the WAV.
Example: a 3-minute recording
You convert a 3-minute CD-quality WAV to a 192 kbit/s MP3.
- WAV size176,400 × 180 = about 30.3 MB
- MP3 size192 ÷ 8 × 180 = 4,320 KB, about 4.2 MB
About seven times smaller
Mono speech at 128 kbit/s would be about 2.8 MB.
Terms on this page
- WAV
- An uncompressed audio format that keeps every sample, with large files.
- kbit/s
- Kilobits per second: the amount of data used for each second of sound.
Common questions
How much smaller is an MP3 than a WAV?
At 192 kbit/s, about one-seventh of the size of CD-quality WAV.
Will I hear the difference?
At 192 kbit/s or above most people cannot tell for everyday listening. Keep the WAV if you will edit the sound further.
Is my file uploaded?
No. Your browser reads and converts the file on your own device. Nothing is sent over the network.
Which bit rate should I choose?
128 kbit/s for speech, 192 for general use, 256 or 320 for music you care about.
Can I convert many files at once?
Yes. Add several files and download each MP3, or use Download all.
Where these numbers come from
- MDN Web Docs — BaseAudioContext.decodeAudioData() How a browser decodes an audio or video file's sound into samples.
- LAME MP3 encoder (lame.sourceforge.io), LGPL The MP3 encoder, here a JavaScript port (lamejs) used unmodified as a separate file.
- Library of Congress — WAVE Audio File Format The structure of a WAV file: a header and 16-bit PCM samples.
- MDN Web Docs — Using files from web applications How a page reads a file you choose without uploading it.
Last verified 2026-10-25 The method on this page is checked against the sources above at least once a year. Spotted something out of date? Tell us and we will fix it.
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