WordPress script initiators and the Core Web Vitals

Sites with parser-initiated scripts script initiator type have a good INP most often: 98%, against 98% of all WordPress sites. Sites with other script initiators script initiators have it least often, at 97%.

Sites with inline scripts script initiator type have a good LCP most often: 70%, against 70% of all WordPress sites. Sites with other script initiators script initiators have it least often, at 66%.

Inline scripts is the most used: 99.9% of WordPress sites. Parser-initiated scripts is 98.7% of WordPress sites.

Alpine sets the script initiator type to parser-initiated scripts on 100% of its sites, and 95% of Alpine sites have a good INP, against 98% of all sites. jQuery sets the script initiator type to inline scripts on 100% of its sites, and 98% of jQuery sites have a good INP.

Alpine sets the script initiator type to parser-initiated scripts on 100% of its sites, and 80% of Alpine sites have a good LCP, against 70% of all sites. jQuery sets the script initiator type to inline scripts on 100% of its sites, and 69% of jQuery sites have a good LCP.

FrameworkScript initiator type on its sitesGood INP

WordPress sites with script initiator type 63,280 sitesInline <script> execution 100%HTML parser (<script src>) 99%Script-injected (tag managers / loaders) 87%Other initiators (workers / preloads) 10%98%

React 2,233 sitesInline <script> execution 100%HTML parser (<script src>) 99%Script-injected (tag managers / loaders) 87%Other initiators (workers / preloads) 13%98%

jQuery 60,311 sitesInline <script> execution 100%HTML parser (<script src>) 99%Script-injected (tag managers / loaders) 88%Other initiators (workers / preloads) 11%98%

Vue 4,844 sitesInline <script> execution 100%HTML parser (<script src>) 99%Script-injected (tag managers / loaders) 80%97%

Alpine 380 sitesInline <script> execution 100%HTML parser (<script src>) 100%Script-injected (tag managers / loaders) 96%Other initiators (workers / preloads) 25%95%

Inline <script> execution HTML parser (<script src>) Script-injected (tag managers / loaders) Other initiators (workers / preloads)

Does the framework explain the script initiator type difference?

Almost every site with parser-initiated scripts script initiator type is a jQuery site, and almost every jQuery site has parser-initiated scripts script initiator type, so the data can't tell parser-initiated scripts script initiator type and jQuery apart. On Vue, 97% of sites with parser-initiated scripts script initiator type have a good INP, against 97% of Vue sites with inline scripts. Within Vue, sites with parser-initiated scripts and inline scripts have a good INP about equally often. On React, 98% of sites with parser-initiated scripts script initiator type have a good INP, against 98% of React sites with inline scripts. Within React, sites with parser-initiated scripts and inline scripts have a good INP about equally often.

Almost every site with inline scripts script initiator type is a jQuery site, and almost every jQuery site has inline scripts script initiator type, so the data can't tell inline scripts script initiator type and jQuery apart. On Vue, 68% of sites with inline scripts script initiator type have a good LCP, against 68% of Vue sites with parser-initiated scripts. Within Vue, sites with inline scripts and parser-initiated scripts have a good LCP about equally often. On React, 61% of sites with inline scripts script initiator type have a good LCP, against 61% of React sites with parser-initiated scripts. Within React, sites with inline scripts and parser-initiated scripts have a good LCP about equally often.

Parser-discovered scripts versus cascading script-injected chains

When scripts are declared in HTML (98.7% of sites, 62,469), the browser preload scanner discovers them immediately (98% good INP, 86ms median). On 87.0% of sites (55,082), scripts are dynamically injected by other scripts such as Google Tag Manager or loader snippets (98% good INP, 86ms median), while 10.4% (6,594) trigger scripts via other initiators (97% good INP, 88ms median).