Stereo to mono
Mix both channels into one, or keep a single side when a microphone was recorded to the left or right only. Mono files are half the size and play the same on every speaker.
Fit Meter
Interviews recorded with one microphone per channel usually want a single side.
Ignored by the lossless formats.
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How to use it
- 01
Add your files
Drop in your stereo recordings.
- 02
Check the settings
Mix both channels, or keep the left or right one on its own — useful when two people were recorded on separate channels.
- 03
Save the result
Press make mono and save the result.
Why it doesn’t upload
Mixing channels is simple arithmetic on the audio, and your browser can do it. There is no reason for the recording to leave your device.
How to check for yourselfWorth knowing
- Mono can’t be turned back into real stereo afterwards. Keep the original if you might need the separation.
- Mixing both channels can make sounds that were panned hard left and right quieter, and anything recorded out of phase can cancel out.
- Lossless files roughly halve in size. Lossy files shrink less, because the encoder already shares data between channels.
- Uses the FFmpeg engine, a one-time 31 MB download.
Questions
Why convert stereo to mono?
Speech recordings don’t need two channels: mono halves the file, sounds identical on a phone speaker, and avoids the problem of a voice only coming out of one ear on headphones.
My interview has one voice per channel. Can I split them?
Choose Left only or Right only and run it twice to get each voice as its own file.
Does making it mono lose quality?
It loses the stereo image by design. Everything else is kept, and if you save to WAV or FLAC nothing further is lost.
Will it halve the file size?
For WAV, FLAC and AIFF, close to it. For MP3, M4A and Opus the saving is smaller, but you can also pick a lower bitrate, since mono needs fewer bits for the same quality.
Read more about this
Other tools
- Audio Converter MP3, WAV, M4A, FLAC, OGG, Opus and older formats, any direction.
- Normalize Loudness Bring a recording to the loudness Spotify, YouTube or podcasts expect.
- Change Volume Make a quiet recording louder or a loud one quieter.
- Extract Audio Save the soundtrack of a video as MP3, WAV, M4A and more.