Render-blocking scripts: use defer and async to show pages sooner

When the browser meets a script tag in the page head without defer or async, it stops building the page until the script is downloaded and run. Several of them in a row can delay the first paint by seconds.

Quick fixes

1. Add defer to your own scripts in the head. They download in parallel and run in order after the HTML is ready.
2. Use async for independent tags such as analytics.
3. Move scripts to the end of the body if you can't edit the tags.
4. Remove what you don't use: old tracking pixels, chat widgets on every page, sliders nobody sees.

WordPress

Performance plugins (for example WP Rocket, Perfmatters, Autoptimize or LiteSpeed Cache) can defer JavaScript and delay third-party scripts until the visitor interacts. Test the site afterwards: some scripts break when deferred.

Shopify and Wix

Review installed apps: each one often adds its own script. Uninstall unused apps and remove leftover code from the theme.

Third-party tags

Load marketing tags through Google Tag Manager, and let them wait for consent (see Consent Mode v2). The SEO audit lists pages with more than two blocking scripts in the head and pages with over 15 external scripts.