Web-based Media Conversion Tools

WebM to MP4 (fixed 1280x720 resolution) (very slow!)

The same as: fmpeg -i input.webm -vf scale=1280:720 output.mp4

WebM to MP4 files (no transcoding, attempts to force high resolutions)

WebM to Audio-only files (opus or wav)

MKV to MP4 (no transcoding)

The same as: fmpeg -i INPUTFILE -vcodec copy -acodec copy output.mp4