Defer/async scripts
Detects render-blocking <script> tags in <head> without defer or async.
Pourquoi est-ce important ?
Scripts without defer or async in the <head> block HTML parsing until they are fully loaded and executed. This delays First Contentful Paint (FCP) and can slow down the page by several seconds.
Comment le corriger ?
Add defer to scripts that can execute after the DOM is loaded. Use async for scripts that are independent of the DOM (e.g. analytics). Move scripts before </body> if not possible.
Ce check note de 0 à 100. Sous 50 c’est un échec, 50 à 89 un avertissement, 90 ou plus c’est bon. Après chaque crawl vous voyez la note par page dans le rapport, avec une courte explication.
Questions fréquentes
Detects render-blocking <script> tags in <head> without defer or async.
Scripts without defer or async in the <head> block HTML parsing until they are fully loaded and executed. This delays First Contentful Paint (FCP) and can slow down the page by several seconds.
Add defer to scripts that can execute after the DOM is loaded. Use async for scripts that are independent of the DOM (e.g. analytics). Move scripts before </body> if not possible.
Exemple
Copiez le code ci-dessous et adaptez le nom de domaine, la marque et le contenu à votre situation.
<script src="app.js" defer></script>