Splitting channels apart is a different job from mixing them together. A field recording made with two separate microphones, a dual mono interview track with one speaker on each side, or a multitrack bounce that stacked two unrelated signals into one stereo file all need their channels pulled apart before either one can be worked with on its own. Trying to isolate a single channel in most consumer audio players is either impossible or requires routing tricks that most people never discover.
The whole process happens on your device. The Web Audio API decodes the file into per channel sample arrays already, so this audio channel splitter simply copies the left channel into one buffer and the right channel into another, then encodes each as its own WAV file without any of the audio ever leaving your browser tab.
When you need to split stereo audio into separate channels
Dual mono interviews and podcast recordings are the most common case. A common recording setup places one guest on the left channel and another on the right, so each speaker's voice can be edited, leveled or transcribed on its own without picking up bleed from the other microphone. Splitting the channels first turns a single awkward stereo file into two clean mono tracks a editor can actually work with independently.
Field recordings and test signals are another. Two microphones spaced apart to capture a room, or a stereo pair used to record two separate synchronized signals, both need the channels separated before analysis or further processing makes sense, since treating the pair as one blended stereo signal would hide exactly the difference between the two microphones that made recording them separately worthwhile.
- Use an audio channel splitter to pull a dual mono interview into two individually editable voice tracks.
- Separate a stereo field recording into its two microphone signals for comparison or further processing.
- Isolate one channel of a stereo test tone or calibration recording for analysis.
- Recover a channel that was accidentally used to carry an unrelated signal in a stereo file.
How this stereo audio splitter separates left and right
A decoded stereo AudioBuffer already stores its samples as two independent Float32Array channels internally, one for the left side and one for the right, since that is exactly how the Web Audio API represents multi channel audio. Splitting is therefore a copy operation rather than a calculation: the left channel's samples are copied unchanged into a new single channel buffer, and the same is done separately for the right channel.
Because no averaging or mixing happens at any point, each resulting mono file is bit for bit the same audio that channel carried in the original stereo recording, just repackaged as its own file with its own header. Nothing about the level, timing or content of either channel changes during the split.
What happens with files that are not standard stereo
A file that is already mono has only one channel to begin with, so there is nothing to separate and the tool declines to run rather than producing two identical copies of the same audio, which would be misleading output for a tool whose entire purpose is separating distinct channels. Files with more than two channels, such as certain surround formats, are read from their first two channels only, since left and right are the two positions this splitter is built to isolate.
If your source file is a true mono recording that only sounds stereo because both channels carry an identical copy of the same signal, splitting it will correctly produce two mono files, and both will sound the same, because that is genuinely what each channel contained. This splitter is the reverse operation of going from stereo to mono channels by averaging, since here every channel is kept intact rather than blended together.
Why does an audio channel splitter output two files instead of one?
The Web Audio API's decodeAudioData method turns the compressed input into an AudioBuffer, exposing each channel through the getChannelData method as a Float32Array of raw samples. This tool reads channel zero into a new single channel AudioBuffer for the left output and channel one into a separate buffer for the right output, keeping the original sample rate for both.
Each of those two mono buffers is then encoded independently through a hand written WAV writer that produces a standard 44 byte RIFF header followed by 16 bit PCM samples. Because the two channel arrays already exist inside the decoded AudioBuffer before any splitting logic runs, there is nothing for this tool to send anywhere. A server based splitter would need your file on its disk to read those same two arrays, which is the step this page skips entirely.
How to split audio into left and right channels
- 1
Add your stereo audio file
Drag a stereo audio file onto the drop area, or click it to browse. MP3, OGG, FLAC, M4A, AAC and WAV are all accepted.
- 2
Confirm it has two channels
The detected channel count is shown once decoding finishes. A mono file has nothing to split.
- 3
Split the channels
Press split. The left channel and the right channel are each copied into their own mono buffer.
- 4
Download each channel
Download the left channel WAV and the right channel WAV separately, or take both files at once.
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Sources and further reading
Frequently asked questions
Common questions about the audio channel splitter.
No. Averaging channels together is what a mono downmix does, which is the opposite of what this tool is for. Each output file is an untouched copy of exactly one channel's samples, so the left channel output and the right channel output remain fully independent of each other.
If both channels of a stereo file already carry an identical signal, splitting it will produce two mono files that sound the same, since that is genuinely what each channel contained. The tool declines to run on a file that is stored as true mono, since there is only one channel to separate in that case.
This splitter reads only the first two channels of a decoded file, treating them as left and right, since those are the two positions it is built to isolate. Additional channels beyond the second, such as those in some surround formats, are not extracted.
Dual mono interviews with one speaker per channel, stereo field recordings from two microphones and files where an unrelated signal ended up on one channel all need the channels pulled apart before they can be edited, transcribed or analysed independently rather than as one blended stereo signal.
Yes. If you only need one side, split the file as usual and keep only the left or right download, discarding the other. The tool always produces both channels together since that is the simplest way to extract audio channel data without guessing which side you will end up needing.
Yes for the samples themselves, since splitting is a copy operation with no averaging or resampling involved. The output is written as 16 bit PCM WAV, so if your source used a higher bit depth internally the WAV write step matches the same bit depth every WAV export from this site uses.
Yes. Both outputs are copied from the same decoded AudioBuffer at the same sample rate and the same length as the source, with no trimming or resampling in between. Placing both files at position zero on separate tracks in any multitrack editor lines them up exactly, sample for sample.