Compression level
Custom reduction
Choose between 10% and 90% compression
Up to 100 MB · MP3, WAV, AAC, OGG · processed in your browser, nothing is uploaded.
First use downloads the processing engine (about 25 MB). It is cached afterwards.
How to compress an audio file
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1
Choose the audio
Select an MP3, WAV, AAC or OGG file, or drag it onto the upload area. The file is processed in your browser.
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2
Set the compression level
Pick a value between 10% and 90%. The higher the percentage, the smaller the file; 50% is a good starting point for most audio.
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3
Compress
Click Compress Audio. The first time, your browser downloads the compressor (FFmpeg), which is then cached.
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4
Download the compressed MP3
Compare the original and new sizes and click Download Compressed Audio. The result is always an MP3 that plays on any device.
What the compression level does
The compressor re-encodes the audio as an MP3 at a lower bitrate. The level you choose is applied to a 320 kbps reference, the highest MP3 quality: 50% produces a 160 kbps file, 70% produces 96 kbps and 90% produces 32 kbps. Since an MP3's size is proportional to its bitrate, a 10-minute recording goes from about 24 MB at 320 kbps to roughly 7 MB at 96 kbps.
WAV files are not compressed at all, so the savings are usually huge: a 50 MB WAV recording can become an MP3 of just a few megabytes with no noticeable difference for speech.
How much to compress, depending on the use
- Voice notes, lectures and meetings: 70% to 80% (96 to 64 kbps). Speech stays clear and the file is small enough for messaging apps and email.
- Podcasts and audiobooks: 60% to 70% (128 to 96 kbps).
- Music for listening on your phone: 40% to 50% (192 to 160 kbps).
- Music you want to keep in good quality: 10% to 30% (288 to 224 kbps).
Privacy and limits
Recordings of meetings, interviews and personal messages are sensitive. That is why compression runs locally with FFmpeg compiled to WebAssembly: the file is not sent to any server, and you can use the tool as often as you like without signing up. The only practical limit is your device's memory, which only matters for very long recordings.
One tip: compressing an MP3 that is already at a low bitrate won't help and can make it sound worse. If the original is already 128 kbps, choosing 50% (160 kbps) will not reduce the size; use 70% or more instead.
Audio compressor FAQ
How do I reduce the size of an audio file?
Select the file, choose a compression level (for example 70%) and click Compress Audio. The resulting MP3 has a lower bitrate and takes up much less space.
What compression level is best for voice messages?
For speech, 70% to 80% keeps the file small while the voice stays perfectly clear.
Which formats can I compress?
MP3, WAV, AAC and OGG, among other audio formats your browser recognizes. The output is always MP3.
Is my audio uploaded to a server?
No. All processing happens in your browser and the file never leaves your device.
Does compressing audio reduce quality?
Slightly, because the bitrate goes down. With speech the difference is barely noticeable; for music, levels up to 50% keep good quality on most headphones.
Complete Guide to Audio Compression: Everything You Need to Know
Audio compression is essential for optimizing file sizes without sacrificing too much quality. Whether you're sharing audio online, saving storage space, or preparing files for different platforms, understanding audio compression can help you achieve the perfect balance between size and quality.
Why Compress Audio?
Audio compression offers numerous benefits for content creators, businesses, and everyday users. By reducing file sizes, you can improve loading times, save storage space, and make sharing easier.
Key Benefits:
- Faster upload and download speeds
- Reduced storage requirements
- Easier sharing across platforms
- Better streaming performance
- Lower bandwidth costs
- Improved user experience
Types of Audio Compression
Understanding different compression methods helps you choose the right approach for your needs.
Lossless Compression
Reduces file size without losing any quality. Best for archival purposes.
Lossy Compression
Achieves significant size reduction by removing some data. Most common for web audio.
Spatial Compression
Reduces redundancy between audio channels for stereo files. Effective for multi-channel audio.
Temporal Compression
Exploits patterns over time to achieve better compression ratios. Used in advanced audio codecs.
Best Practices for Audio Compression
Follow these guidelines to get optimal results from audio compression:
Choose appropriate quality settings for your use case
Test compressed audio on target devices
Consider your audience's internet connection speeds
Use modern formats like AAC when possible
Maintain appropriate bitrates for different uses
Keep original files as backups
Compress once to avoid quality degradation
Use appropriate sample rates for different uses
Common Compression Issues and Solutions
Learn about frequent problems and how to resolve them:
Excessive quality loss during compression
Use higher bitrate settings or lossless compression
Compressed files still too large
Reduce bitrate or use more aggressive compression
Compressed audio doesn't play on some devices
Use widely supported formats like MP3 or AAC
Compression artifacts make audio sound distorted
Use higher quality settings or lossless compression for critical audio
Why Choose Our Audio Compressor?
100% Private
Files processed locally, never uploaded to servers
Lightning Fast
Compress audio quickly in your browser
Quality Control
Choose compression level for optimal results
Completely Free
No registration, no hidden costs
Secure Processing
Advanced client-side processing
Universal Compatibility
Works with all modern browsers and devices