Short answers for the converter on wav2mp3.org. The tool itself is on the home page.
FAQ
Is WAV to MP3 free?
Yes. Encoding uses LAME in the browser. Nothing is sent to our servers.
What bitrate should I pick?
192 kbps for music, 128 kbps for voice, 96 kbps for speech notes, 256–320 kbps if you want extra headroom.
Do you support FLAC or M4A?
If the browser can decode it, yes. WAV, FLAC, OGG and M4A are the usual inputs.
Why resample to 44.1 or 48 kHz?
LAME expects a short list of sample rates. Auto picks 44.1 or 48 kHz; you can force either.
Stereo or mono?
Keep stereo for music. Mono mixes both channels and roughly halves the bitrate budget for voice.
How many files at once?
Ten. Each file is encoded in sequence.