PageSpeed: Use Efficient Cache Lifetimes

Pages with resources that are not cached. HTTP caching can speed up your page load time on repeat visits.

When a browser requests a resource, the server providing the resource can tell the browser how long it should temporarily cache it.

For any subsequent request for that resource, the browser uses its local copy rather than gets it from the network.

How to Analyse in the SEO Spider

To populate this filter the PageSpeed Insights API must be connected via ‘Config > API Access > PSI’.

View URLs with this issue in the ‘PageSpeed’ tab and filter and use the lower ‘Lighthouse Details’ tab to click on the issue on the left-hand side, and see details of the static assets on the right-hand side.

Bulk export the pages and resources via ‘Reports > PageSpeed > Use Efficient Cache Lifetimes’.

What Triggers This Issue

This issue is triggered when pages have resources that are not cached.

Lighthouse considers a resource ‘cacheable’ if it’s a font, image, media file, script of stylesheet with a 200 response – and doesn’t have an explicit no-cache policy.

All cacheable subresource requests should have a cache lifetime of at least 30 days (2592000 seconds).

Chrome for Developers believe all static assets should follow the this decision tree: cacheable resources should have a very long lifetime (30 days or 1 year).

How To Fix

Cache static resources using HTTP caching. A long cache lifetime can speed up repeat visits to pages.