Subsetting a font is the 80% nobody takes

A variable font covering every script is several hundred kilobytes, and a site rendering English and Turkish needs a fraction of it.

$ pyftsubset inter-var.ttf 
    --unicodes='U+0000-00FF,U+0100-017F,U+2000-206F' 
    --layout-features='kern,liga,calt' 
    --flavor=woff2 --output-file=inter-subset.woff2

# 412 KB → 68 KB

# and the unicode-range, so the browser only fetches the
# subset it needs:
@font-face { unicode-range: U+0000-00FF, U+0100-017F; }

Dropping layout features is where the rest of the saving is and is also where a font stops rendering correctly — calt and kern matter for readability and liga is usually optional. Including the Turkish dotted and dotless i in the range is the case that gets forgotten and produces a page where one letter falls back to a different typeface.