convert stereo MP3 to mono
An MP3 has one fixed bitrate per file, not per channel: encoding in mono at the same 128kbps produces a file the same size as the stereo original, not half. In a direct test of this tool, two seconds of audio produced exactly 32,600 bytes both in mono and in stereo at 128kbps, and only dropped to 16,300 bytes (half) once the mono export used 64kbps.
Bitrate, not channel count, is what decides the final size in a CBR MP3 like this tool produces.
The half-size result only showed up once the bitrate was also cut in half, not just the channel count.
Neither voice disappears, because summing two channel-specific signals still preserves both, it only lowers each one's level.
Averaging sums L and R and halves the result, which preserves centred content (vocals, kick) but can cancel anything recorded in opposite phase. The L and R modes simply discard one channel: you lose whatever only existed on the other side, but you gain a guarantee that nothing will cancel. When the correlation strip shows negative stretches, that is exactly the trade-off to weigh.
Not at the same bitrate: a test at 128kbps produced exactly 32,600 bytes in both mono and stereo, because the encoder allocates the same bit budget per file, not per channel. The real reduction only shows up if you also pick a lower bitrate, like 64kbps, after converting.
Because decoding and re-encoding an MP3 applies a second lossy pass over the same audio, discarding information again near the transients the first pass already cut. Starting from the WAV skips that second generation, since the mono mixdown runs over lossless PCM and only one compression pass happens at the end.
Yes. The mono file's single channel is sent equally to both speakers during playback, so there is no positioning loss or restriction to one side, only the absence of whatever stereo separation the original had.
Your audio is decoded and processed in your browser. No file is ever uploaded to the server.