Is Compress audio free? Is there a watermark?

Yes — Compress audio is free to use with no sign-up or watermark. Very large files can still be limited by your browser's available memory and processing resources.

Do my files get uploaded to a server?

No. Compress audio runs entirely in your browser with WebAssembly, so your MP3, WAV, M4A, AAC file never leaves your device and nothing is stored or seen by us.

What can I put in, and what do I get out?

Compress audio accepts MP3, WAV, M4A, AAC and gives you back a MP3 file. You can also set bitrate before you run it. Actual codec support depends on what the bundled engine or browser decoder can read.

Can I control the output?

Yes — you can adjust bitrate, so you decide the balance between file size and quality.

Free tools · Compress & resize

Compress audio

Re-encode an audio file as a 64, 96, or 128 kbps MP3 for email, messaging, or podcast delivery. Output size and quality depend on the source and bitrate. Browser-only, no upload or watermark.

Runs entirely in your browser. Your file is never uploaded — no watermark, no account.

Drop a file or click to chooseMP3, WAV, M4A, AAC

Get a better result

Best for: Voice notes, podcast previews, music references, and email attachments where delivery size matters more than archival fidelity.
Input → output: MP3, WAV, M4A, or AAC input becomes an MP3 at 64, 96, or 128 kbps through lossy LAME encoding.
Quality tip: Start at 96 kbps for speech and compare music at 128 kbps. Listen for watery transients, smeared ambience, and brittle high frequencies.
Know before running: Re-encoding is lossy, and low-quality source audio cannot be improved. An input already below the chosen bitrate may not become smaller and can lose detail again.
Next step: Audio to MP3 when broader source support or a higher delivery bitrate is the priority afterward.

How to use Compress audio

1
Choose your file. Drop a supported MP3, WAV, M4A, AAC file into the tool, or click to select one. It stays on your device — nothing is uploaded.
2
Pick your settings. Adjust the available options, then press Run. The first processing run loads the browser engine before conversion begins.
3
Download. Review the result, then download the finished file from your browser with no watermark.

Frequently asked questions

Is Compress audio free? Is there a watermark?: Yes — Compress audio is free to use with no sign-up or watermark. Very large files can still be limited by your browser's available memory and processing resources.
Do my files get uploaded to a server?: No. Compress audio runs entirely in your browser with WebAssembly, so your MP3, WAV, M4A, AAC file never leaves your device and nothing is stored or seen by us.
What can I put in, and what do I get out?: Compress audio accepts MP3, WAV, M4A, AAC and gives you back a MP3 file. You can also set bitrate before you run it. Actual codec support depends on what the bundled engine or browser decoder can read.
Can I control the output?: Yes — you can adjust bitrate, so you decide the balance between file size and quality.