Local channel conversion

Stereo to Mono

Convert stereo or multi-channel standalone audio into a mono MP3 or WAV file directly in the browser.

Downmix audio to mono

Upload an audio file, choose MP3 or WAV, and export a one-channel version for narration or compatibility.

Drop an audio file here MP3, WAV, M4A, AAC, FLAC, OGG, or WebM audio up to 1.5 GB.

Audio processing happens locally in this browser tab. Large uncompressed files can still use a lot of memory, especially on older laptops.

FFmpeg downmixes channels into one mono track, so left and right content are combined.

Mono can make spoken audio more predictable across phones, laptops, and conferencing tools.

The desktop app is better for long recordings, repeated exports, and finishing work after screen recording.