Redis caching
Redis object caching for WordPress and shops
Redis object caching stores the results of common database queries in memory, so WordPress does not have to ask the database the same question again and again. It is available on every Limitless Hosting plan, and it helps most on busy sites, membership sites and WooCommerce shops, where page caching alone cannot help every visitor.
How it works
Where object caching fits
- Page requestWordPress starts building a page
- Ask the cacheRedis is checked for the data first
- Saved in memoryFound data comes back instantly
- Or ask the databaseMissing data is fetched and stored
Two kinds of cache
Page cache and object cache do different jobs
| Page cache | Object cache (Redis) | |
|---|---|---|
| What it stores | Whole finished pages | Results of database queries |
| Best for | Pages every visitor sees the same | Logged-in users, baskets, searches |
| Helps WooCommerce basket and checkout | Little, as these pages are personal | Yes, reduces database work |
| Provided by | LiteSpeed Cache | Redis, connected with a plugin |
Most sites benefit from using both together.
Switch it on
Connecting WordPress to Redis
Install a connector plugin
Use the LiteSpeed Cache plugin or another object cache plugin.
Enable object cache
Choose Redis as the cache method and save the settings.
Check it is connected
The plugin shows a connection status. It should report the cache as active.
Test the site
Browse as a logged-in user and place a test order to be sure everything works.
Who benefits
Sites that gain the most
WooCommerce shops
Baskets and checkouts are personal, so page caching cannot help. Object caching can.
Membership and course sites
Logged-in users get dynamic pages, which benefit from cached queries.
Large content sites
Sites with many posts and complex queries spend less time on the database.
In depth
What object caching actually saves
Every WordPress page asks the database dozens of questions: which posts to show, what the site title is, what options are set. Many of these answers do not change between requests, yet WordPress asks again each time.
An object cache keeps those answers in memory. Memory is far faster than a database query, so repeated questions are answered almost instantly and the database is left free for work that really changes.
The gain is largest on busy sites and on pages that cannot be fully cached, such as baskets, checkouts and logged-in dashboards.
Troubleshooting
If something looks wrong after enabling it
Most problems are fixed by flushing the object cache from the plugin settings. If a change you made does not appear, flush and reload. If the plugin reports that it cannot connect, check that the cache method is set to Redis and contact our live chat.
- Flush the object cache after large updates
- Do not run two object cache plugins together
- Test logged-in pages as well as the home page
- Check the status screen shows the cache as connected
Choosing
Is object caching worth switching on for your site?
Switch it on if your site is WordPress with a shop, a membership area, a forum or a lot of content. These make many database queries per page, and a cache saves real time.
You can leave it off for a small brochure site that already serves cached pages, because there is little database work to save. If you are unsure, test with it on and off, and keep whichever is faster for your pages. Measure with the same page, at similar times of day, a few times each, because one run can mislead you. A change of a few hundredths of a second is noise, and a change you can feel on a phone is worth keeping.
Faster dynamic pages, included
Redis object caching comes with every plan from 84p a month (£10.03 billed yearly).
FAQ
Common questions
Is Redis available on all plans?
Yes. Redis object caching is included with every plan.
Will it speed up every site?
It helps sites that make many database queries. A simple static brochure site will see little change.
Do I need technical skills?
No. You connect it with a plugin and a few settings.
Is it safe?
Yes. It caches data, not your site files, and clearing the cache is harmless.
Keep reading
Related pages
Speed up your database-heavy site
Redis object caching and LiteSpeed on every plan.