Cache Rules

A cache rule controls caching for the addresses it covers; whichever rule matches decides how a request is cached.

Create a cache rule

1. Rules → Add Rule → Cache Rule.
2. Set the addresses it applies to (/*, /assets/*, etc.).
3. Choose what to cache and for how long.
4. Click Save.

Scope

Scope	What it caches
Static files	Images, CSS, JS, fonts, downloads. Safe default.
Everything	Every cacheable response, HTML included.

No “custom” scope — narrow the rule’s paths to cache less.

Note

Static files are cached by default — see How Caching Works. Add a rule to change freshness, force-cache, or exclude paths.

Caution

Everything caches HTML too — on logins, carts, or dashboards, one visitor may see another’s page. Use it only for identical pages, with safety checks on.

TTL, refresh, query string

• TTL — how long a copy stays fresh before nsin re-fetches.
• Background refresh — nsin re-fetches on a schedule while still serving the current copy, so visitors never wait.
• Include query string — on, ?page=1/?page=2 cache separately; off, they share one copy.

Safety checks

On by default so caching can’t leak private data. Turn one off only if the response is identical for everybody.

Check	What it does
Skip requests with an Authorization header	Doesn’t cache authenticated requests.
Skip responses that set a cookie	A session cookie is personal.
Honour no-store from the visitor	Respects a browser’s no-store.
Honour your server’s Cache-Control	Server’s headers decide.
Use your server’s max-age	Uses server’s max-age, not the rule’s TTL.
Never cache WordPress admin/login	Leaves /wp-admin and /wp-login.php alone.

Should I cache it?

If the page…	Do this
Same for everyone (blog post, image)	Cache it
Differs per person (account, cart)	Don’t cache, or keep safety checks on
Changes constantly (live scores)	Short TTL, or background refresh

Common questions

A private page got cached and showed the wrong data. Exclude that path, then purge once. Usual cause: an Everything-scope rule with the cookie check off.

My changes aren’t showing. Purge, or use developer mode.

Which rule applied to a request? Check the Nsn-Cache-Status header — see Proxy Headers.