Fewer than half of scripts use async or defer

The async and defer attributes let a script tag load without blocking the browser from painting the page. This check measures what share of a page's scripts use one of these attributes. On this site, coverage is low, under 50% of script tags, meaning the loading strategy is inconsistent: some scripts are optimised and others still block rendering, which undercuts the benefit of the ones that are. Mixed loading strategies mean the page still suffers rendering delays from the scripts that were missed, even though some scripts have already been fixed, so the site isn't getting the full benefit of the work already done to speed it up. Your developer should audit every script tag on the page. For each one that isn't needed before first paint, add async if its execution order doesn't matter, or defer if the order does matter. Budget about one hour for a typical page template.