Audio Channel Converter
Fix and rearrange audio channels in one place. Mix stereo or 5.1 surround down to mono or stereo with the standard downmix, swap left and right when a recording is reversed, put one channel on both sides when the other is empty or noisy, or split a file into separate mono files – one per channel – for editing.
- Files stay on your device
- No sign-up
- Free to use
Channels
Surround (5.1, 7.1) is mixed down with the standard downmix matrix, keeping centre dialogue clear.
Processing happens on your device; your audio is not uploaded.
How to use Audio Channel Converter
- Drop an audio file onto the page.
- Choose the conversion.
- Choose the output format.
- Convert and download.
Audio Channel Converter features
Downmix
Surround and stereo to stereo or mono.
Swap
Exchange left and right.
Single channel
Left or right on both sides.
Split
One mono file per channel.
Standard matrix
Dialogue stays clear.
Private
Processed in your browser; nothing is uploaded.
When to use Audio Channel Converter
- Fixing interviews recorded with one microphone per channel.
- Correcting reversed stereo recordings.
- Downmixing 5.1 film audio for headphones.
- Splitting multitrack recordings for editing.
Audio Channel Converter FAQ
How is 5.1 mixed down?
With FFmpeg’s standard downmix matrix: centre and surround channels are blended into left and right at reduced levels, and dialogue stays centred.
When should I use “left channel on both sides”?
When only the left channel contains the recording – common with a single microphone plugged into a stereo input.
What does split produce?
One mono file per channel: left and right for stereo, six files for 5.1.
Is the sound otherwise changed?
No processing beyond the channel change.
Why does the first run take longer?
Re-encoding uses FFmpeg compiled to WebAssembly (about 32 MB), which is downloaded once and then cached.
Which formats can I use?
MP3, WAV, M4A/AAC, OGG, Opus, FLAC, WMA and AIFF, and the audio of MP4, MOV, WebM and MKV videos. Save in the original format or as MP3, M4A, WAV or FLAC.
Working with audio channels
Most audio is stereo: two channels intended for left and right speakers. Recordings do not always use them as intended. A podcast recorded with two microphones may have one person per channel; a camera with a single external microphone may record only the left side; a cable mix-up may reverse left and right. Film audio often comes as 5.1 surround with six channels.
The channel converter handles these cases with FFmpeg’s pan and channel filters. Swapping exchanges the two channels. The single-channel options copy one side to both, removing a silent or noisy channel. Downmixing uses the standard coefficients, so surround tracks sound balanced on stereo speakers and headphones and dialogue from the centre channel stays clear.
Splitting writes each channel to its own mono file, named by its position – left, right, centre and so on. That is useful for editing two-person recordings separately or for inspecting surround mixes.
For a quick stereo-to-mono or mono-to-stereo conversion with more options, see the dedicated tools.
If you are unsure what a file contains, play it with headphones and listen to each side, or check the channel count shown in the file statistics above the controls before choosing a conversion.
Processing runs in your browser.