Mono playback is cleaner on a single speaker (phone, voice recordings, podcast episodes that were stereo-tracked by accident), and the file size drops by roughly 50 percent.

Will it sum-cancel vocals?

No — Average and Sum modes preserve the center. For vocal removal, use the vocal remover instead, which subtracts L from R.

Average mode attenuates 6 dB so clipping is almost impossible. Sum mode can clip if both channels already peak near 0 dBFS.

Stereo to Mono | MakeMySounds

Stereo to MonoLocal

Collapse stereo files to mono. Pick how the channels combine, preview the result, and export as MP3 or WAV.

Drop an MP3 or WAV file here

or click to browse

⎆Your audio never leaves your browser. The conversion runs locally via the Web Audio API.

How to use Stereo to Mono

Drop a stereo file
Drag in an MP3 or WAV. The tool shows the number of channels in the original.
Pick a combine mode
Average is the safe default. Sum is louder but can clip. Left/right pick one channel only.
Preview
Play the mono result before downloading.
Export
Download as MP3 or WAV. The output is half the size of the stereo original.

Frequently asked questions

Why flatten to mono?: Mono playback is cleaner on a single speaker (phone, voice recordings, podcast episodes that were stereo-tracked by accident), and the file size drops by roughly 50 percent.
Will it sum-cancel vocals?: No — Average and Sum modes preserve the center. For vocal removal, use the vocal remover instead, which subtracts L from R.
What about clipping?: Average mode attenuates 6 dB so clipping is almost impossible. Sum mode can clip if both channels already peak near 0 dBFS.

Want to remove vocals using L/R subtraction?Vocal remover
Need a specific bitrate?Audio compressor