In response to blip #119970
@garfieldfromgarfield:
Use FFmpeg and you don't have to pay anything or register to dubious websites:
$ ffmpeg -hide_banner -i ./somevideo.mp4 -c:v libvpx-vp9 -b:v 0 -crf 30 -pass 1 -an -f null /dev/null && \ ffmpeg -hide_banner -i ./somevideo.mp4 -c:v libvpx-vp9 -b:v 0 -crf 30 -pass 2 -c:a libopus -b:a 128k -vbr on -compression_level 10 ./someothervideo.webm