Stillmore

Free Mono and Stereo Converter

Select mono to combine the channels or stereo to export a two-channel MP3.

Files stay in this browser. Choose up to 64 MB per job.

Only edit videos you own or have permission to edit. Stillmore does not offer a YouTube video downloader.

Fold the kitchen soundtrack into mono

This stereo excerpt follows the steak from the chopping board towards the plate. Compare the spread on headphones with the centred, single-channel MP3.

The chef slices the seared steak.
Original
Edited output

How to change an audio track’s channel count

  1. Load the source

    Choose an audio recording or a video that contains the track you need.

  2. Choose mono or stereo

    Select Mono to fold the track into one channel, or Stereo for a two-channel deliverable.

  3. Check the balance

    Download the converted MP3 and listen with headphones, especially if the original channels sounded different.

Choose a channel layout for the job

A channel conversion changes where sound is carried. Listen to both speech and background elements after the change.

Centre a one-sided microphone

If a spoken take plays through one ear, try a mono copy and check the speaker’s level.

Review a mix on one channel

Fold a stereo cue to mono and listen for instruments or vocals that become quieter.

Supply a two-channel file

Convert a mono take to stereo when the receiving edit session asks for two channels.

Prepare a spoken reference

Make a mono review file for a voice performance where left-right placement carries no useful information.

Mono and stereo converter FAQ

Why can I hear the presenter in only one ear?

A stereo recording may carry the microphone on one side. Try a mono export and listen on headphones. If the two original channels cancel when mixed, return to the recording and select the clearer channel in your editor.

Does stereo conversion create a wider sound?

A mono recording can be carried in two channels, but the conversion cannot recover separate left and right performances.

Can I export only the left channel?

The Mono option downmixes the available channels. Choosing an individual input channel requires a channel selector in an editor.

Why did part of a stereo mix get quieter in mono?

Signals with opposing phase can partially cancel when combined. Compare the result with the original before approving the mono file.

Will the export contain one channel or two?

Choose Mono to write a one-channel MP3. Choose Stereo for a two-channel MP3.

Can I change the channel count of a video soundtrack?

Yes. Choose a video with sound. The result is an audio-only MP3 with the channel count you selected.

How can I check a downmix before delivering it?

Listen to the original and mono versions on the same headphones at the same volume. Pay attention to distant voices or instruments that become unusually faint.