Compress Audio — Reduce File Size Free Online
Shrink your audio file size while preserving sound quality. Instantly. No sign-up required.
How to compress audio
- 1Upload your audio file using the drop zone above
- 2Choose your target bitrate
- 3Click "Compress Audio" to reduce the file size
- 4Compare the before and after sizes, then download
About This Tool
Large audio files eat through email attachment limits and storage quotas. Our free compress audio tool re-encodes your audio at a lower bitrate, dramatically reducing file size while keeping the sound quality you need.
Choose from four bitrate levels: 64 kbps for voice-only content, 128 kbps for a good balance, 192 kbps for high-quality music, or 256 kbps when you want the best possible compressed quality. The tool outputs MP3 for maximum compatibility.
Everything runs in your browser via FFmpeg.wasm. Your audio files are never uploaded to any server. No watermarks, no daily limits, no account required.
Frequently Asked Questions
64 kbps works for voice recordings and podcasts. 128 kbps is good for general use. 192 kbps is great for music. 256 kbps gives near-transparent quality where most listeners cannot hear the compression.
Results depend on the original file. A 320 kbps MP3 compressed to 128 kbps will be roughly 60% smaller. WAV and FLAC files will see 80-95% reduction.
The tool accepts MP3, WAV, OGG, FLAC, AAC, M4A, and WMA files. The output is always MP3 for maximum compatibility.
No. All compression happens locally in your browser using WebAssembly. Your files never leave your device.
Re-encoding an already compressed MP3 at a lower bitrate will reduce quality. For the best results, start from the highest quality source (WAV or FLAC) when possible.