Pages are built once, stored on disk and served before WordPress loads. You find these settings on the Cache tab, in the Page cache card.
Cache pages for visitors
The main switch. Turn it off to stop caching and empty the stored pages.
Keep pages for
How long a stored page is used before it is rebuilt on its next visit. Choose 1 hour, 3 hours, 6 hours, 10 hours, 24 hours, 2 days or 7 days. The default is 10 hours.
Security tokens in forms last 12 to 24 hours. If you choose more than 12 hours, a cached form can stop working. 10 hours or less is safest.
Separate copy for phones (mobile cache)
Turn this on only if your theme shows different HTML on mobile. Most modern themes use the same HTML for all screens and do not need it.
Advanced options
These are inside Advanced, marked “Expert, may break some sites”.
Serve the old copy while rebuilding (stale while revalidate)
When a page expires, the next visitor still gets the old copy at once, and a fresh copy is built in the background. It needs PHP-FPM or LiteSpeed. On other servers the option is disabled.
Cache 404 pages and feeds
Stores “page not found” pages and RSS feeds too. Up to 1,000 error pages are kept.
Cache for logged-in users
Gives each logged-in person a private cached copy for up to 6 hours. Editors and administrators are never cached. Copies are removed when the person logs out or their profile or role changes.
Things that change for a person without the page changing, such as a cart count, unread badges or access that expires, can look out of date for up to 6 hours. If you use a membership plugin, test this carefully.