KaTeX weighs about the same if you do care about those metrics, however.
In case anyone wants to look at actual numbers about how much KaTeX weighs for a simple mathematics page: https://news.ycombinator.com/item?id=44614133
Quoting the relevant part from that link:
katex.min.css 23.6 kB katex.min.js 277.0 kB auto-render.min.js 3.7 kB KaTeX_Main-Regular.woff2 26.5 kB KaTeX_Main-Italic.woff2 16.7 kB ---------------------------------- Total Additional 347.5 kB
In case anyone wants to look at actual numbers about how much KaTeX weighs for a simple mathematics page: https://news.ycombinator.com/item?id=44614133
Quoting the relevant part from that link:
Of course, if the page uses more symbols in various sizes, then a few more fonts files (.woff2) need to be pulled in which case the weight of KaTeX would increase a bit too. Each font file weighs between 4 kB and 28 kB.