Bundle size, loading strategy, and runtime cost.
View all tags
Before shipping the new tools I ran a mobile pass. Eight of nine pages showed zero overflow; the datapack generator was 80px too wide at 320px.
The annoying part: you cannot see this on a desktop browser.
The scariest part of mobile support is "looks fine to me". I started with my eyes and screenshots, and missed several problems that only appear at real device widths. Then I switched to measuring with a headless browser — and found that screenshots themselves can lie.
"Will adding tools make the homepage slower?" was my own biggest worry. The answer is not to minify harder, but to separate two things: do not pay for a page you never opened, and do not make the first click wait.