01 — The tool
Edit left and right audio channels separately
The free Loudness.ai Audio Channel Editor gives you separate controls for the left and right sides of a recording. Change each channel's volume, mute a side, swap channels or invert polarity. Use the original and processed previews to check the balance before exporting a new file.
Choose stereo, left only, right only or a mono mix for the output. For example, a microphone recorded only on the left can be exported as a single channel without keeping the empty right side. Use the Stereo to Mono Converter when you simply want to combine both sides without adjusting them individually.
02 — How it works
How to edit stereo audio channels online for free
Inspect the original channels
Open your recording and listen to both sides. Identify whether the issue is an uneven volume, reversed sides, an empty channel or a sound that changes when both channels play together.
Adjust volume and routing
Set the left and right levels from 0 to 200 percent. Use mute or swap when needed. Compare any polarity change carefully; raising channel volume can also make peaks too strong.
Preview the output layout
Select stereo, one side or a mono mix. Prepare the preview, listen with headphones and check the intended speaker balance. Export MP3 or WAV with the sample rate and quality you need.
03 — Practical uses
Correct channel balance in interviews and recordings
A microphone on one side
Keep the channel containing the voice and export it alone. This is useful when a stereo recording has speech only on one side. Trim the take with the Audio Cutter if the beginning or end also needs editing.
Uneven stereo recordings
Lower the louder channel or raise the quieter side in small steps. Compare a section where both sides should sound balanced. Keep intentional instrument placement in mind before making both channel volumes identical.
Channel order and polarity
Swap the sides when left and right were recorded in the wrong order. A polarity inversion changes a signal's sign; compare the result with both channels playing. The Audio Level Checker can help you review levels after export.
04 — Frequently asked questions
Audio Channel Editor questions
Can I mute the left or right channel?
Yes. Each side has its own mute control. You can also choose left-only or right-only output to export the channel you want as a separate mono recording.
What does swapping channels do?
It exchanges the left and right sides. The sound recorded on the left plays on the right, and vice versa. It does not change the timing or pitch of either channel.
What does invert polarity mean?
It reverses the sign of the selected signal. This can affect how related sounds combine between channels. It is not a timing adjustment, so listen carefully rather than assuming it fixes every phase problem.
Will raising a channel to 200 percent improve quality?
It increases that channel's level. It does not recover missing detail, and high levels can cause clipping. Start with smaller changes and check the strongest part of the recording before exporting.