Script initiators and the Core Web Vitals
97.7% of audited sites (192,444) load scripts directly from the HTML parser (92% good INP, 98ms median), while 75.0% inject scripts via other scripts (92% good INP, 102ms median) and 18.2% trigger scripts from other initiators (89% good INP).
96.5% of sites use inline scripts script initiator type, and 92% of those sites have a good INP, against 92% of all sites.
18.2% of sites use other script initiators script initiator type, and 82% of those sites have a good LCP, against 82% of all sites.
Core Web Vitals pass rate
Sites with inline scripts script initiator type have a good INP most often: 92%, against 92% of all sites. Sites with other script initiators script initiators have it least often, at 89%.
Sites with other script initiators script initiator type have a good LCP most often: 82%, against 82% of all sites. Sites with script-injected scripts script initiators have it least often, at 80%.
Script initiator type usage
Parser-initiated scripts is the most used: 97.7% of sites. Inline scripts is 96.5% of sites.
Understanding script initiators
Parser-discovered scripts versus cascading script-injected chains
When scripts are declared in HTML (97.7% of sites, 192,444), the browser preload scanner discovers them immediately (92% good INP, 98ms median). On 75.0% of sites (147,825), scripts are dynamically injected by other scripts such as Google Tag Manager or loader snippets (92% good INP, 102ms median), while 18.2% (35,826) trigger scripts via other initiators (89% good INP, 104ms median).
Prefer declarative <script defer> tags in HTML over JavaScript loader chains that inject second- and third-level scripts at runtime, and throttle tag-manager injection so late scripts do not fire during user input. Across all audited sites, 97.7% use parser-initiated scripts (92% good INP) and 75.0% use script-injected loaders (92% good INP).
How script initiator type plays out per platform
What the field data shows when you isolate a single CMS or framework.
WordPress 65,494 sites 87.1% of WordPress sites load script-injected scripts, while 10.4% with other initiators pass INP at 95%.
Across 65,494 WordPress sites, 98.7% load scripts from the HTML parser (97% good INP, 96ms median), 87.1% inject scripts from other scripts (96% good INP), and 10.4% use other initiators (95% good INP, 103ms median).
Shopify 8,570 stores 99.9% of Shopify stores use script-injected loaders, while 19.1% with other initiators pass INP at 90%.
Across Shopify storefronts, 99.8% load parser-initiated scripts (93% good INP), 99.9% load script-initiated scripts (93% good INP, 112ms median), and 19.1% have other script initiators (90% good INP, 121ms median).
React & Next.js 9,570 sites 99.6% of React & Next.js sites declare scripts in HTML and 95.1% also load script-initiated chunks (93% good INP).
Across 9,570 React sites, 99.6% use parser-discovered <script> tags (92% good INP), 95.1% load script-initiated chunks (93% good INP), and 71.6% use other initiators (93% good INP).
By Arjen Karel · 210,902 crawled sites (126,761 with phone Chrome field data, 196,999 sites with script initiator type, October 2026). How we measured.