Audio Compressor
How to Compress Audio Online
- 1
Upload your audio file
Drop your audio file into the upload area or click to browse. MP3, WAV, FLAC, OGG, AAC, M4A, and WMA are all supported.
- 2
Adjust the quality setting
Use the bitrate slider to balance file size and audio quality. Higher bitrates (192+ kbps) sound great but produce larger files. Lower bitrates (64–96 kbps) are ideal for voice recordings, podcasts, or when storage space is the priority.
- 3
Compress and download
Click "Compress Audio" and download the smaller MP3 file. Everything runs locally in your browser — your audio is never sent anywhere.
Understanding Audio Bitrate
Bitrate (measured in kilobits per second, or kbps) controls how much data is used to represent each second of audio. Higher bitrate means more data — better quality but a larger file. Lower bitrate means less data — smaller file but reduced fidelity.
Virtually indistinguishable from lossless. Use for music archival or when quality is the priority. File sizes are 2–3× larger than 128 kbps.
The sweet spot for most music. Near-transparent quality for casual listening with a significantly smaller footprint than 320 kbps.
Acceptable quality for music, great for podcasts and voice. The de facto standard for streaming radio. Most listeners cannot tell the difference from 192 kbps on typical speakers.
Noticeable compression artifacts on music with complex audio. Suitable for voice-only content (podcasts, voice memos, audiobooks) where a tiny file size matters.
Heavy compression artifacts. Usable for voice recordings in limited-bandwidth contexts (voice messages, radio streaming) but not recommended for music.
Variable Bit Rate encoding uses higher bitrates for complex audio passages and lower for simple ones. Better overall quality-to-size ratio than constant bitrate (CBR).
Frequently Asked Questions
- Is my audio uploaded to a server?
- No. SonoCut processes your audio entirely in your browser using WebAssembly. Your files never leave your device — no upload, no server, no storage.
- What's the maximum file size?
- We recommend files under 500 MB for best performance. Files up to 1 GB are supported but may be slower depending on your device.
- Will compression reduce audio quality?
- Yes — compressing to a lower bitrate involves some quality loss. Higher bitrate settings (192 kbps and above) produce results that are indistinguishable to most listeners. Lower bitrates (64–96 kbps) reduce quality noticeably but achieve much smaller file sizes. Use the slider to find the right balance for your use case.
- What format is the compressed output?
- The compressed file is saved as MP3, the most universally compatible compressed audio format. MP3 plays on every device, operating system, and platform without additional software.
- How much smaller will my file be?
- It depends on the source format and the bitrate you choose. A WAV or FLAC file converted to MP3 at 128 kbps can be 10× smaller. An existing MP3 re-encoded at a lower bitrate will see a more modest reduction — typically 30–70% depending on the original quality.