Rules

Two questions on one screen, because they are the same question from both ends: which pages are worth caching, and which must never be.

Cache on#

By default, Everywhere on the site. The alternatives are The front page only, Shop and product pages (the shop, products, and every product archive — categories, tags, brands and attributes) or Only what I choose below, which opens the detail:

• Places — the front page, the blog index, search results, the 404 page, and the shop page if you run one.
• Post types — posts, pages, products, and any custom post type your other plugins register. With Everywhere on the site, new post types are cached automatically; with Only what I choose below, tick them here.
• Archives — the listing pages for any public taxonomy: categories, tags, product categories.
• Specific pages — search for individual pages, posts or products by name when ticking a whole kind of content is more than you meant.

The cart, the checkout and the account pages are deliberately absent from this list. They are never cacheable whatever anybody ticks, so offering them would be offering a switch that does nothing.

Exclude#

The same control backwards: quick ticks for the places most often left out, a search box for naming individual pages, and a box for address patterns.

Excluded URLs takes a path, one per line. A path on its own excludes that page only, with or without its trailing slash: /blog/ is the blog page, not the posts under it. stands for anything, so /members/ covers everything under it. These are the one exclusion applied before WordPress loads — everything else on this screen is decided after the page is built, and simply stops it being stored. (Before 1.1.29 the fast path read a line as part of an address, so /blog/ also excluded every post under it. If you relied on that, add /* to the line.)

You can paste an address straight from the browser, letters from other alphabets included. Earlier versions saved such an address as // (the front page), //* (every page) or /, or with letters missing; a line saved like that keeps doing what it did, so if the box holds one you did not mean, delete it and paste the address again.

The admin, login, REST API, cart and checkout are already excluded and do not need listing.

Cookie names, under Cookie Exclusions, takes cookie names. Logins, sessions and carts are already handled.

Ignored Query Parameters is the one worth understanding. Parameters listed here are stripped before the cache is looked up, so an advert click and a direct visit share one cached page. Everything not listed is kept, so a filtered product list or page two of an archive still caches separately — which is what most caching plugins get wrong by treating any query string as uncacheable.

A trailing covers a family: utm_. The list starts with the tracking and click IDs that carry a new value on every visit: the utm_* family, Google's gclid, gad_source, gbraid, wbraid and srsltid (Merchant Center's tag on organic product results), and the IDs Meta, Microsoft, TikTok, X, LinkedIn, Yandex, Mailchimp, HubSpot, Klaviyo and Marketo add. When an update adds one, a list you have saved gets it once; one you took out stays out, and an emptied list stays empty.

Saving this screen clears the cache, because a page stored under the old rules is one the new rules would have refused.