Term Kind Topic What it is
Device Class Baseline Reference Device, Slow-Tier Baseline practice Web Performance Budgets A named device and network profile, chosen from the slow end of your real user population, against which every performance budget and acceptance test is measured - so that "fast" means fast for the users who a…
Long Task Main-Thread Blocking Task, Long Animation Frame metric Web Performance Budgets Any single piece of work holding the browser's main thread for more than 50 ms, during which no input is handled and nothing is painted - the unit in which an unresponsive page is actually measured.
Performance Budget Enforcement practice Web Performance Budgets A stated limit on bundle size or a timing metric that fails a build when exceeded, which is what turns performance from a periodic project into a constraint.
Third-Party Weight Budget Tag Budget, Non-Application Script Allowance metric Web Performance Budgets An enforced allowance for scripts the application build does not produce - count, bytes and main-thread time - with a named owner and a technical enforcement point, because these are the scripts a bundle-size …
Web Performance Budget practice Web Performance Budgets An enforced limit on payload size, resource counts or timing metrics, checked automatically so regressions fail the build rather than accumulating.