Convert WAV to MP3 Online — Free & Adjustable Bitrate

Compress WAV files to MP3 with selectable bitrate — 128, 192, 256, or 320 kbps.

How It Works

1Upload your WAV by dragging it into the drop zone or clicking to browse.
2Click Convert to encode as MP3 — everything runs locally in your browser.
3Click Download to save your MP3 file.

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.

From the blog

Why Browser-Based Tools Are More Private Than Online Converters
Most online converters upload your files to a server. Browser-based tools never do. Here's exactly what changes for your privacy — and how to verify it yourself.
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Frequently Asked 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.

Is my file uploaded to a server?

No. Transmute processes everything locally in your browser using JavaScript and the Canvas API. Your files never leave your device — there is no server, no upload, no cloud processing.

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