How it works
Average stereo channels to mono or duplicate mono into stereo.
Mono is(L+R)/2, which may cancel opposite-polarity sounds. Stereo duplicates mono; no spatial effect is invented.
Select local files; nothing is uploaded. Preview the result before downloading.
Example
Mono: (L+R)/2 · Stereo: M → L=M, R=M
Limits
PCM WAV input only:8/16/24/32-bit integer or32-bit float, mono/stereo,8000–96000Hz. Output:16-bit PCM WAV. MP3/M4A/OGG/FLAC are not supported in v1.
Memory is checked from duration, channels and sample rate before decoding. The working budget is64MiB mobile or128MiB desktop; source PCM≤32MiB, duration≤180s.