Free Online Stereo to Mono
Downmix, or isolate left and right.
Drag & drop your audio file here
or
Max file size: 100 MB · MP3, WAV, FLAC, OGG
Original
beats per minute
musical key
Mono averages left and right (with -6 dB compensation to avoid clipping).
Processing…
Result
How it works
The Downmixer collapses stereo (or multi-channel) audio into a single channel three ways: true mono (an average of left and right with level compensation so nothing clips), left-only, or right-only. Mono files are smaller, play identically on every device, and are the standard choice for spoken word.
Channel isolation is a rescue tool as much as a creative one: a podcast recorded with one dead microphone, a vinyl rip with a damaged channel, or a stereo file with different content per side can all be salvaged by keeping the good channel.
Processing is a straightforward per-sample operation performed client-side in your browser. Your files never leave your device and nothing is uploaded anywhere.
Frequently asked questions
When should I convert stereo to mono?
Mono is ideal for podcasts and voice recordings (smaller files, consistent playback), for checking mix phase issues, and for systems with a single speaker. Club PA systems are often mono too.
Will mono be quieter or clip?
Neither here: the channels are averaged with proper level compensation, so mono lands at a sensible loudness without clipping or volume loss.
What are the left/right-only modes for?
Some recordings hide different content in each channel - dual-mono interviews, karaoke tracks, or old stereo with a damaged side. Isolating one channel rescues the good half.
Is there a file size limit? Is it private?
Files up to 100MB are supported. Downmixing runs entirely in your browser - your audio never leaves your device.