How to convert stereo to mono
- Drop your audio file into the box or choose it. Several files at once work too.
- Choose Mono to mix left and right into one channel, Stereo to copy a mono file to both sides, or Left only or Right only to keep one side as mono.
- Listen to the Result, ideally on headphones, then download. The note next to the file says what changed.
When mono makes sense
- Podcasts and voice recordings: a single voice has no real left and right. In mono, someone listening with one earbud hears everything.
- Hearing in one ear: a stereo mix can hide instruments or voices on the side someone can’t hear. Phones offer a mono audio setting, but a mono file works in any player.
- Small speakers: phone speakers and many smart speakers have little or no stereo separation, so checking a mix in mono shows what those listeners will hear.
- Recordings with one side missing: a mono microphone plugged into a stereo camera or recorder input often ends up on the left channel only. Mixing to mono fixes it in one step.
Mono mixes the left and right channels equally. Surround sound files are first mixed down to stereo in the standard way, with the centre channel shared between left and right so dialogue isn’t lost, and then mixed to one channel.
Why some audio changes in mono
Stereo works partly through small differences between the two sides. When a sound is in step on both sides, adding them together keeps it at full strength. When a sound is out of step, the two copies cancel each other, and the more out of step they are, the more disappears.
Most commercial music is mixed so it still sounds right in mono, and speech recorded with one microphone is never a problem. If a stereo recording with two microphones, or a heavily processed electronic track, comes out hollow, keep it in stereo. Your audio is processed in your browser and never uploaded.