Audio Converter
This free audio converter tool converts audio between MP3, M4A, Opus, WAV and FLAC, lets you set the bitrate, and can trim to a start and length — all powered by ffmpeg running in your browser. Drop a file, choose your options, and download the result without anything ever being uploaded.
Runs entirely in your browser via ffmpeg.wasm — the file never leaves your device.
How to use Audio Converter
- 1 Drop an audio (or video) file onto the box or click to browse.
- 2 Pick an output format — MP3, M4A, Opus, WAV or FLAC — and choose a bitrate for the lossy formats.
- 3 Optionally set a Start time and Length in seconds to trim just the section you want.
- 4 Click Convert (the first run downloads the audio engine once), then preview and download the result.
Frequently asked questions
Is my audio uploaded to a server?
No. Conversion runs entirely in your browser via ffmpeg.wasm, so your file never leaves your device — safe for private recordings.
Which formats can I convert to?
You can export to MP3, M4A (AAC), Opus, WAV or FLAC. WAV and FLAC are lossless, while the others let you choose a bitrate from 96 up to 320 kbps.
Can I trim the audio while converting?
Yes. Enter a Start time in seconds and a Length in seconds to keep only that section; leave Length blank to convert through to the end.
Why does the first conversion take longer?
The first run downloads the roughly 31 MB audio engine once. After that it's cached, so subsequent conversions start much faster.