How much smaller does a WAV get as an MP3?
A lot. A 16-bit stereo WAV runs about 10 MB per minute; the same audio is roughly 2.4 MB per minute at 320 kbps and 1 MB per minute at 128 kbps, a 4x to 10x reduction.
Does converting WAV to MP3 reduce quality?
Yes, MP3 is lossy, so some detail is discarded. At 320 kbps the difference is inaudible to most people. Keep the WAV as your editing master and use the MP3 for sharing.
Are my audio files uploaded?
No. The conversion happens entirely in your browser, and the file never leaves your device. Files up to 200 MB are supported, free, with no sign-up and no ads.