How to Enable Redis Cache in WordPress

If your WordPress website is running slow, learning how to enable Redis cache in WordPress can significantly boost its performance. Redis works by storing frequently accessed data in memory, reducing the need to repeatedly load information from the database every time someone visits a page. By enabling Redis caching, you can make your site load much faster and provide a smoother experience for your visitors.

In this blog, we’ll show you how to easily set up Redis cache for your WordPress site on different Linux servers. Even if you’re not a tech expert, just follow the steps and your site will be faster in no time!

Prerequisites

• A working WordPress site
• Access to your server (SSH/root or sudo user)
• Redis server installed
• PHP Redis extension installed
• WordPress Redis plugin (like Redis Object Cache)

Step 1: Install Redis Server

On Ubuntu/Debian

#apt update
#apt install redis-server 

On CentOS 7/8

#yum install epel-release
#yum install redis

On AlmaLinux 8/9

#dnf install redis

Enable and start Redis:

#systemctl enable redis
#systemctl start redis

Test Redis:

Test redis using the command:

#redis-cli ping

Output: PONG

Step 2: Install PHP Redis Extension

For PHP 8.x (All OS)

#apt install php-redis  # Ubuntu/Debian
#yum install php-pecl-redis -y  # CentOS
#dnf install php-pecl-redis -y  # AlmaLinux

Restart your web server:

#systemctl restart apache2   # for Apache
#systemctl restart nginx     # for Nginx

Step 3: Install & Enable Redis Plugin in WordPress

Log in to your WordPress Dashboard

Go to Plugins → Add New

Search for Redis Object Cache

Click Install, then Activate

Then go to:

Settings → Redis

Click Enable Object Cache

If Redis is working, you’ll see a Connected message.

Step 4: Configure wp-config.php with Redis Constants

To fine-tune Redis behavior or work with custom setups, add the following constants before the line that says /* That’s all. */ in your wp-config.php file:

// Redis Configuration
define( 'WP_REDIS_HOST', '127.0.0.1' ); // Redis server address
define( 'WP_REDIS_PORT', 6379 );        // Redis default port
define( 'WP_REDIS_PASSWORD', '' );      // Redis password if set (optional)

When should you edit these?

If Redis is hosted on another server (change WP_REDIS_HOST)

If you’re using Redis authentication (set WP_REDIS_PASSWORD)

If you’re using a different Redis database index (e.g., to isolate cache per site)

After making these changes, go back to the Redis plugin settings and flush the cache to apply.

Final Tips

Redis works best when combined with page caching plugins like LiteSpeed Cache or WP Rocket.

Monitor Redis memory usage using:

#redis-cli info memory

To flush Redis cache manually:

#redis-cli flushall

Conclusion

Setting up Redis cache for your WordPress site is a smart move to enhance speed, scalability, and overall performance. Whether you’re running on Ubuntu, CentOS, or AlmaLinux, the process is straightforward — install Redis, connect it with WordPress using a plugin, and fine-tune it through your wp-config.php file for better control.

By offloading repeated database queries to Redis, your site can handle more traffic with fewer resources, delivering a faster and smoother experience to your visitors.

If you’re unsure how to enable Redis cache in WordPress, it’s always a good idea to seek expert assistance to ensure it’s set up correctly and securely. A professional team offering reliable server management services can help you configure Redis caching, optimise your website’s performance, and handle any server-level adjustments.