Fold a stereo file down to a single mono channel — useful for voice recordings, podcasts, or systems that only support mono playback.
Stereo to Mono combines the two channels of a stereo file into a single channel. Mono halves the file size, plays identically on every speaker, and suits voice recordings, phone systems, PA speakers and podcasts delivered in mono.
Before converting it measures the correlation between left and right so you know whether the fold-down is safe — out-of-phase recordings can cancel when summed, making instruments vanish.
Average mode outputs (L+R)/2 — safe levels and the standard. Power-sum outputs (L+R)·0.7071, which preserves loudness for decorrelated material but may exceed the original peak, so a limiter follows. “Left only” or “Right only” keeps just one channel — useful when one microphone failed or contains the better take. Correlation is the Pearson coefficient of the two channels: +1 identical, 0 unrelated, −1 inverted.
Deliver mono to save bandwidth.
Mono for voice systems.
Check how a mix sounds on one speaker.
Use the good channel when the other is bad.
| Modes | Average · power sum · left · right |
|---|---|
| Mono check | Left/right correlation shown |
| Size saving | ≈ 50% for the same per-channel bitrate |
It loses stereo width, not frequency content.
Out-of-phase signals subtract when summed.
Yes, roughly by half when exporting to WAV, since there's only one channel of samples instead of two.
Anything panned left or right is mixed into the center, so the stereo width is lost — this is expected for a mono conversion.
This tool runs entirely in your browser using the Web Audio API. Nothing is uploaded, stored or shared — there is no server to send your file to, so it works offline once the page has loaded.
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