Compress Audio Files
Shrink audio file size by re-encoding at a lower bitrate - batch process up to 20 files, all processed locally in your browser.
Output quality
Already-compressed formats (MP3, OGG, AAC, M4A, OPUS) are re-encoded at your chosen bitrate. Lossless sources (WAV, FLAC) are converted to MP3, since compressing lossless audio means becoming lossy - there's no smaller-but-still-lossless option beyond FLAC's own compression.
Drag & drop files, or browse
Up to 20 audio files at once
How it works
Upload audio files
Drop up to 20 files at once.
Choose a bitrate
Low, standard, or high quality.
Download savings
Get individually compressed files or a ZIP bundle.
Compression re-encodes the audio at the bitrate you choose, using FFmpeg compiled to WebAssembly - the same encoders (libmp3lame, libopus, etc.) used by desktop tools, just running inside your browser tab instead of on a server.
Lossless sources (WAV, FLAC) are handled differently: WAV is converted to MP3 since there's no smaller-but-lossless WAV variant, while FLAC gets its own maximum lossless compression level rather than being converted to a lossy format.
Frequently asked questions
4 questionsWAV is uncompressed by design, so there's no smaller-but-still-WAV option - shrinking it means encoding to a lossy format. MP3 is the default target since it's the most universally supported.