Convert stereo to mono
Mix both sides into one, or fix a recording where the sound comes out of only one ear. The result is an MP3 made on your own computer and never uploaded.
- Never uploaded
- No size limit
- No sign-up
- Free
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Quick answer: To convert stereo to mono, drop the sound file into the tool at the top of this page, choose "Mix into mono" and press "Make mono". If the sound plays in only one ear, choose the side that has it instead, and it is played in both ears. A video works too: you get its sound. It happens in your browser, so the file is never uploaded. It is free, with no sign-up and no watermark.
Updated
How it works
- Drop your soundMP3, M4A, WAV, OGG and more, or a video to use its sound. It stays on your computer.
- Choose what to doMix both sides into one, or copy the left or the right side to both ears.
- Download the MP3Pick the MP3 quality and save the result.
Sound in only one ear
Some recordings play in one earphone only, for example when a microphone was plugged into the wrong input. Mixing would make such a recording quieter, because half of it is silence. Instead choose "Left side in both ears" or "Right side in both ears", whichever side has the sound, and that side plays in both. To find the side, play the file with earphones and notice which ear hears it.
Mixing to mono
"Mix into mono" blends the left and right sides into one. It suits a voice recorded in stereo that you want to play from a single speaker, or a stereo file where both sides hold the same voice. If the mixed result sounds thin or quiet, the two sides were partly opposite to each other and cancel out when added. In that case, pick one side instead of the mix.
Sound from a video
Drop a video and the tool takes its sound; the picture is not kept. To turn a video into a plain MP3 without changing the sides, use video to MP3.
Measured, not promised
Timed on 21 Oct 2026 in Chrome on a 2019 Intel MacBook (an older laptop) with a one-minute recording of spoken sound. Newer computers are faster; real files vary. More results.
Why your audio never leaves your computer
Your audio is converted by your own computer, inside this tab, and never uploaded. That is why there is no length limit and no sign-up. How it works.
Questions
Why does my audio play in only one ear?
The recording has sound on one side only. A microphone plugged into the wrong input is one cause. Copy the side that has sound to both ears.
Will mixing to mono lose quality?
Both sides are blended into one, so the stereo width is gone. For a single voice this is rarely noticeable.
Can I use a video?
Yes, you get the sound of the video as an MP3.
Is my file uploaded?
No. It is converted inside this browser tab and saved straight back to your computer.
Can I use a video file?
Yes. Drop a video and you get its sound.