What This Is.

a free, in-browser tool that shrinks an audio file to a smaller mp3 by re-encoding at a lower bitrate. useful when a voice memo is too big to send by email, when you need a web-friendly version of a long interview, or when you want an archive copy that fits more on a usb stick.

output is always mp3 because mp3 is the universal "this will play anywhere" target. pick a bitrate and the tool does the rest.

Bitrate Guide.

320 kbps — transparent, archival. indistinguishable from the source for almost all listeners.
192 kbps — high quality. the right default for music.
128 kbps — balanced. the legacy "good enough for music" standard.
96 kbps — clear speech. the right default for interviews, podcasts and voice memos.
64 kbps — compressed speech. fits more on email and chat attachments. quality drops audibly on music.

Nothing Uploads.

most "compress audio" tools are server-side services. you upload your file, their server processes it, you download the smaller file. for most files that's fine — but for sensitive material (interviews under embargo, client-confidential audio, off-the-record recordings, audio you'd rather not have copies of on a third-party server), it isn't.

this tool runs ffmpeg.wasm directly in your browser. the file you drop is read into the browser's memory, decoded locally, and re-encoded locally. no network request happens at any point during the compression. you can verify this in your browser's network tab — and we wrote a five-minute walkthrough on doing exactly that audit.

How To Use It.

drop your audio (or video) file into the target above (or click to choose).
pick a target bitrate. 96k is a good default for speech; 192k for music.
hit compress. the smaller mp3 downloads to your machine; nothing reaches us.