📂 Choose a file⚙️ Pick settings⬇️ Save the result
Compress audio now
PRIVATE TOOLNo upload. Works in your browser.
Need more on iPhone? ✅ Pick format · ✅ Set target size · ✅ Batch compress · ✅ Split, trim, merge, convert. Get the app ->
Pick audio to begin.
Help & FAQ
How to make audio smaller safely
❓ Quick answers
How do I compress audio, step by step?
- Choose your audio file. Click Choose audio above or drag a file in. MP3, M4A, WAV, AAC, and voice memos all work.
- Pick a bitrate. Lower bitrate = smaller file. 48–64 kbps is ideal for voice; 128 kbps is a good balance for music; 192 kbps keeps more detail.
- Click Compress. Just Compress makes a smaller M4A and downloads it automatically.
Which bitrate should I choose?
| Content | Bitrate | Best for |
|---|---|---|
| Voice memo / interview | 48–64 kbps | Smallest size, email & messaging |
| Podcast / spoken word | 64–96 kbps | Clear speech, small file |
| Music (recommended) | 128 kbps | Good quality, easy to share |
| Music — keep detail | 192 kbps | Higher fidelity |
Why compress in the browser instead of uploading?
Most online audio compressors upload your file first. Just Compress keeps your recording on your device, which is better for voice memos, interviews, and unreleased music.
How do I compress audio on iPhone?
- In Safari: open this page on your iPhone, choose a file from Files or your voice memos, and compress it in the browser.
- With the app: install the free Just Audio Compressor app to make recordings smaller and share them faster from your iPhone.
Is it really free?
Yes — the online tool is free with no sign-up, no watermark, and no file-size paywall.
Are my files uploaded?
No. Your audio stays on your device.
What file do I get back?
A compressed M4A (AAC) file, which plays on iPhone, Android, Mac, and Windows and is smaller than the equivalent MP3.