How to optimize GIF file converted to WEBM?

Question

linux

There is a gif in 22mb (1920x1080)
It needs to be optimized for use on the site.
I converted it to mp4 and then to webm using ffmpeg, but the quality became terrible, although the size is good - ~200kb
What can be done at all?
And what is available from under linux?

Answer 1

ffmpeg with correct options

Answer 2

I'm afraid you have two ways
1. find the source "and convert it to html5"
2. write everything in html5
Because you can't shrink it so much, there won't be an adaptive, etc., etc.
file in the studio