Convert stereo audio to mono

How to Convert to mono

1. 1

   Add your audio file

   MP3, WAV, FLAC, M4A, AAC, OGG or Opus, up to 200 MB. Twenty files at a time if you have a batch.

2. 2

   Choose average, left or right

   Average blends both channels evenly. Left and right keep one side and discard the other entirely.

3. 3

   Click Convert and download

   The result is a single-channel WAV, roughly half the size of the stereo original at the same quality.

Average, left or right: they solve different problems

Average is the right answer when both channels carry the same performance and you want one channel instead of two: the two sides are blended in equal parts, so nothing is lost except the stereo image. Left and right exist for a different situation, and it is a common one. An interview recorded with two microphones on separate channels, a camera where one input picked up a hum, a video call captured with the far end on one side: in all of these, one channel is what you want and the other is a problem. Averaging would fold the problem into the result at half volume. Picking a side discards it completely.

Why averaging halves each channel instead of adding them

Two channels carrying nearly the same sound, added together as they are, produce a signal twice as large, which means everything loud in the original slams into the ceiling and comes back distorted. Taking half of each keeps the result inside the same range as the input, so the perceived loudness barely changes and nothing clips. There is one case where averaging does lose sound rather than just the stereo image: if some element sits in the two channels exactly out of phase, the two halves cancel and it disappears. This is rare in normal recordings and common in deliberately widened material, which is worth knowing before you mix down a heavily processed track.

When mono is the better choice

Spoken word is the clearest case. A podcast, an audiobook, a lecture recording or a voice memo carries no stereo information worth keeping, and mono halves the file size for identical intelligibility. Phone systems, radio, most Bluetooth speakers and many messaging apps collapse audio to mono anyway, so doing it yourself gives you control over how it happens instead of leaving it to whatever the playback chain decides. Mono also removes a whole class of problem: a file that sounds fine in headphones but nearly disappears on a mono speaker because of phase cancellation cannot behave that way once it is already mono.

Files that are already mono

Nothing breaks. The single channel is passed through unchanged and the page says so rather than pretending it did work. Choosing left or right on a mono file also returns that same channel — asking for the right channel of a file that has only one is not treated as an error, because the intent is clear and the result is exactly what was asked for.

Frequently asked questions