# How to cache 404s, search and feeds

> Extend caching past ordinary pages — cover 404s, search results, RSS feeds and the REST API, and add your own rules and a maintenance bypass.

- Category: Cache
- Canonical: https://xspeedcache.com/docs/advanced-cache/

---

[Page Cache](https://xspeedcache.com/docs/page-cache/) covers your ordinary pages and posts. But a busy site serves plenty of other requests — someone mistyping a URL, a visitor searching, a feed reader polling, an app calling your REST API — and each of those runs full WordPress every single time. **Advanced Cache** extends coverage to those requests, and gives you a place to write your own caching rules.

> **Where to find it**
>
> 1. In your WordPress admin, click **xSpeed Cache** in the left menu.
> 2. In the xSpeed Cache sidebar, open the **Cache** group.
> 3. Click the **Advanced Cache** card.
>
> *Shortcut: open `wp-admin/admin.php?page=xspeed#/cache/cache-coverage` directly.*
>
> ⭐ The features on this panel are part of **xSpeed Pro**.

![The three Advanced Cache tabs](https://xspeedcache.com/_astro/advanced-cache-tabs.CKxYTCNg.png)

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## Tabs on this panel

This panel is a hub — it owns no settings of its own. Six features live across its three tabs, and each tab has its own guide:

| Tab | Feature | Tier | Guide |
| --- | --- | --- | --- |
| **What to cache** | Cached 404s and search results | ⭐ Pro | [How to cache 404s and searches](https://xspeedcache.com/docs/what-to-cache/) |
| **Feeds & API** | Cached feeds and REST responses | ⭐ Pro | [How to cache feeds and the REST API](https://xspeedcache.com/docs/feeds-and-api/) |
| **Rules & bypass** | URL rules and maintenance bypass | ⭐ Pro | [How to add cache rules and bypasses](https://xspeedcache.com/docs/rules-and-bypass/) |

Each tab has its own address, so you can link straight to one:

| Tab | URL |
| --- | --- |
| What to cache | `#/cache/cache-coverage` |
| Feeds & API | `#/cache/cache-coverage/beyond` |
| Rules & bypass | `#/cache/cache-coverage/rules` |

---

## Which one should you use?

These features aren't equally valuable, and turning all six on isn't the goal. Match them to what your site actually gets:

- **A site under bot traffic or with old broken links** — [404 caching](https://xspeedcache.com/docs/what-to-cache/) is the biggest win here. Rendering a 404 template costs the same as rendering a real page, and bots probe missing URLs relentlessly.
- **A content site with a visible search box** — [search caching](https://xspeedcache.com/docs/what-to-cache/). Search queries are among the most expensive things WordPress does, and popular terms repeat far more than you'd expect.
- **A blog with feed subscribers** — [feed caching](https://xspeedcache.com/docs/feeds-and-api/). Feed readers poll on a schedule whether or not anything changed.
- **A headless site or one with an app front end** — [REST API caching](https://xspeedcache.com/docs/feeds-and-api/).
- **Anything with unusual URL patterns** — [custom cache rules](https://xspeedcache.com/docs/rules-and-bypass/) for the cases the built-ins don't cover.

> 💡 **Everything here builds on [Page Cache](https://xspeedcache.com/docs/page-cache/).** If the main page cache is off, none of these have anywhere to store anything. Start there.

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## A note on safety

Two of these extend caching into territory where a careless setting can leak data between visitors, and both ship with guards:

- **[REST API caching](https://xspeedcache.com/docs/feeds-and-api/)** never caches authenticated or write requests. The panel still warns you to add rules only for public, non-personalised routes — because a route that varies per user can leak data even on an anonymous `GET`.
- **[search caching](https://xspeedcache.com/docs/what-to-cache/)** never caches for logged-in users, and never caches empty searches.

The general principle across this panel: cache what's identical for everyone, never what's personal to one visitor.

---

## Related

- [How to enable Page Cache](https://xspeedcache.com/docs/page-cache/)
- [How to activate your licence](https://xspeedcache.com/docs/license/)
- [How to read your cache diagnostics](https://xspeedcache.com/docs/cache-diagnostics/)