Script initiators and the Core Web Vitals

Sites with inline scripts script initiator type have a good INP most often: 99%, against 99% of all sites. Sites with other script initiators script initiators have it least often, at 99%.

Sites with inline scripts script initiator type have a good LCP most often: 86%, against 86% of all sites. Sites with script-injected scripts script initiators have it least often, at 86%.

Parser-initiated scripts is the most used: 97.7% of sites. Inline scripts is 96.5% of sites.

Wix sets the script initiator type to inline scripts on 100% of its sites, and 100% of Wix sites have a good INP, against 99% of all sites. Joomla sets the script initiator type to parser-initiated scripts on 100% of its sites, and 100% of Joomla sites have a good INP.

Wix sets the script initiator type to inline scripts on 100% of its sites, and 92% of Wix sites have a good LCP, against 86% of all sites. Joomla sets the script initiator type to parser-initiated scripts on 100% of its sites, and 93% of Joomla sites have a good LCP.

PlatformScript initiator type on its sitesGood INP

Sites with script initiator type 196,999 sitesHTML parser (<script src>) 98%Inline <script> execution 96%Script-injected (tag managers / loaders) 75%Other initiators (workers / preloads) 18%99%

Adobe Commerce 1,095 sitesInline <script> execution 100%Script-injected (tag managers / loaders) 98%HTML parser (<script src>) 98%Other initiators (workers / preloads) 18%100%

Wix 5,825 sitesHTML parser (<script src>) 100%Inline <script> execution 100%Other initiators (workers / preloads) 100%Script-injected (tag managers / loaders) 100%100%

Squarespace 2,258 sitesHTML parser (<script src>) 100%Inline <script> execution 100%Other initiators (workers / preloads) 90%Script-injected (tag managers / loaders) 67%100%

Joomla 2,551 sitesHTML parser (<script src>) 100%Inline <script> execution 99%Script-injected (tag managers / loaders) 39%Other initiators (workers / preloads) 27%100%

Drupal 3,295 sitesInline <script> execution 100%HTML parser (<script src>) 100%Script-injected (tag managers / loaders) 82%Other initiators (workers / preloads) 14%100%

WordPress 65,494 sitesInline <script> execution 100%HTML parser (<script src>) 99%Script-injected (tag managers / loaders) 87%Other initiators (workers / preloads) 10%100%

Shopify 8,570 sitesInline <script> execution 100%Script-injected (tag managers / loaders) 100%HTML parser (<script src>) 100%Other initiators (workers / preloads) 19%99%

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

Does the platform explain the script initiator type difference?

On WordPress, 100% of sites with inline scripts script initiator type have a good INP, against 100% of WordPress sites with parser-initiated scripts. Within WordPress, sites with inline scripts and parser-initiated scripts have a good INP about equally often. On Shopify, 99% of sites with inline scripts script initiator type have a good INP, against 99% of Shopify sites with parser-initiated scripts. Within Shopify, sites with inline scripts and parser-initiated scripts have a good INP about equally often.

On WordPress, 76% of sites with inline scripts script initiator type have a good LCP, against 76% of WordPress sites with parser-initiated scripts. Within WordPress, sites with inline scripts and parser-initiated scripts have a good LCP about equally often. On Shopify, 97% of sites with inline scripts script initiator type have a good LCP, against 97% of Shopify sites with parser-initiated scripts. Within Shopify, 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 (97.7% of sites, 192,444), the browser preload scanner discovers them immediately (99% good INP, 49ms median). On 75.0% of sites (147,825), scripts are dynamically injected by other scripts such as Google Tag Manager or loader snippets (99% good INP, 50ms median), while 18.2% (35,826) trigger scripts via other initiators (99% good INP, 54ms median).