Compress an Audio File
Shrink Audio Size With a Bitrate Slider
Need to use Compress an Audio File right now?
Lower bitrates shrink the file more aggressively; higher bitrates preserve more fidelity.
Drop an audio file, or click to browse
Processed locally in your browser — never uploaded
Lower bitrates shrink the file more but reduce audio fidelity — 128kbps is a common good-enough balance for spoken word, 192-256kbps for music.
Features
- Runs entirely in your browser
- Privacy-first — your data is never uploaded
- Real-time, instant results
- 100% free, no sign-up required
- Works on desktop, tablet, and mobile
- No installation needed
Who uses this tool?
About Compress an Audio File
A large audio file — a long recording, a high-bitrate music file, a lengthy podcast episode — sometimes needs to shrink down for email attachment limits, storage constraints, or faster uploads. This tool re-encodes audio at a bitrate you choose, giving direct control over the trade-off between file size and audio fidelity.
A real FFmpeg build compiled to WebAssembly performs the re-encode entirely inside your browser, producing an MP3 at your chosen constant bitrate — lower bitrates shrink the file more aggressively but reduce audio fidelity, higher bitrates preserve more detail at a larger size.
The bitrate slider ranges from 32kbps (heavily compressed, suitable mainly for spoken word where fidelity matters less) up to 256kbps (near-transparent quality for most listeners, appropriate for music), covering the full practical range most compression needs fall into.
Before and after file sizes are shown once compression completes, so you can immediately judge whether the result meets your size target or whether a different bitrate setting would strike a better balance.
How it works
- Upload your audio file. The file loads into the browser-based FFmpeg engine.
- Choose a bitrate. Lower shrinks the file more; higher preserves more fidelity.
- Compress and download. See the before/after size and save the smaller file.
Examples
Shrinking a podcast episode for email
Input
large audio file, 96kbps setting
Output
a much smaller MP3, still clear for spoken word