Mono / Stereo Audio Converter
Convert decoded audio to mono or stereo locally in your browser, with explicit channel-mixing behavior and WAV export.
How channel conversion works
For mono output, Build 105 averages all decoded input channels sample-by-sample. For a mono source converted to stereo, the mono signal is duplicated into left and right. For sources with two or more channels converted to stereo, this foundation uses the first two decoded channels.
When to use it
Mono can reduce data size for speech or material that does not require spatial separation. Stereo is useful when a downstream workflow requires two channels. Converting mono to stereo does not create genuine stereo imaging because both channels contain the same original signal.
Phase and multichannel warning
Averaging stereo to mono can reduce or cancel content when left and right contain opposite-phase material. For files with more than two channels, this bounded Build 105 tool is not a surround downmix engine and does not apply cinema/broadcast downmix coefficients.
Quality, metadata and privacy
Processing is local and output is 16-bit PCM WAV. Source tags, artwork and codec metadata are not preserved. The original selected file is never overwritten.
FAQ
Does stereo conversion make mono wider? No. It duplicates mono. Will mono always sound the same? Not necessarily; phase relationships can change the summed result.
Related tools
Use Sample Rate Converter to standardize sample rate, then Audio Merger or Crossfade when you need compatible channel counts.