Up to -80% · 64/96/128 kbps · Free · No Upload
Compress Audio Online Free — Reduce MP3 and WAV by up to 80%
Reduce the size of any audio by choosing the quality (64/96/128 kbps), right in your browser. Ideal for WhatsApp and email.
100% local processing: your file never leaves your device. Once the page loads, it even works offline.
Supported formats:.mp4 files up to 300 MB — processed locally · Video and virtually any audio format are also accepted — we extract the audio automatically.
How it works
- 01
Upload the audio
Any common format, up to 300 MB.
- 02
Choose the quality
64 kbps (voice, maximum compression), 96 kbps (balanced), or 128 kbps (music). For voice audio, 64-96 kbps sounds nearly identical to the original.
- 03
Download the lightweight file
A 50 MB WAV becomes a ~5 MB MP3 — ready for WhatsApp (16 MB limit), email, and uploads.
Frequently asked questions
Why compress audio online?
WhatsApp limits audio attachments to 16 MB and emails to ~25 MB — compressing to 64-96 kbps solves it without audible loss for voice.
What if I need the text from this audio?
After compressing, you can transcribe the file with AI using VoxScriber: 30 free minutes per month, with automatic punctuation and speaker identification. Ideal for WhatsApp audios, meetings, and interviews.
Is Compress Audio Online Free really free?
Yes, free and unlimited. The processing happens in YOUR browser (WebAssembly), so we have no server cost — and you don't need to create an account.
Is my file sent to any server?
No. All processing is local (FFmpeg compiled to WebAssembly running on the page). The file never leaves your device — it even works offline after the page loads.
Is there a size or quantity limit?
The limit is 300 MB per file (browser memory). There is no limit on the number of uses. For larger files, VoxScriber processes on the server with uploads up to 5 GB.
Does it work on mobile?
Yes — any modern browser (Chrome, Safari, Firefox, Edge) on desktop or mobile. On older phones, large files may take longer.
Need the text from this audio? Transcribe it with AI — 30 min free
Create free account →30 minutes/month free. No credit card required.