If you want to improve your website performance, especially for WordPress or high-traffic applications, using an object caching system like Redis or Memcached can significantly reduce server load and database queries.

In this guide, you’ll learn:

• What Redis is
• What Memcached is
• Key differences between Redis and Memcached
• How to install and start them
• Which one is better for WordPress

What Is Redis?

Redis

Redis (Remote Dictionary Server) is an open-source, in-memory data structure store used as:

• Database
• Cache
• Message broker

Unlike simple caching systems, Redis supports:

• Strings
• Hashes
• Lists
• Sets
• Sorted Sets
• Persistence (optional)

Redis stores data in memory but can also write to disk for durability.

What Is Memcached?

Memcached

Memcached is an open-source, high-performance distributed memory caching system.

It is designed to:

• Reduce database load
• Store simple key-value pairs
• Improve dynamic web applications

Memcached does NOT support complex data types or persistence.

Redis vs Memcached: Key Differences

When Should You Use Redis?

Use Redis if:

• You need persistence
• You need advanced data structures
• You want replication and high availability
• You are running WooCommerce
• You want better WordPress object caching

Redis is ideal for:

• Large WordPress sites
• eCommerce websites
• High-traffic applications

When Should You Use Memcached?

Use Memcached if:

• You want simple caching
• You need multi-threaded performance
• You don’t need persistence
• You want lightweight caching

Memcached is ideal for:

• Small to medium websites
• API response caching
• Temporary cache storage

How to Install and Start Redis (Ubuntu)

Install Redis

sudo apt update
sudo apt install redis-server

Start Redis

sudo systemctl start redis

Enable Auto Start

sudo systemctl enable redis

Test Redis

redis-cli ping

If working:

PONG

How to Install and Start Memcached (Ubuntu)

Install Memcached

sudo apt install memcached

Start Memcached

sudo systemctl start memcached

Enable Auto Start

sudo systemctl enable memcached

Check Status

sudo systemctl status memcached

Default Port:

11211

Redis or Memcached for WordPress?

For WordPress, Redis is generally recommended because:

• Better object cache handling
• WooCommerce compatibility
• Data persistence option
• More active development

Popular WordPress plugins support Redis object caching more robustly.

Memcached works well but is more basic.

Performance Comparison

Redis is slightly heavier but more powerful.
Memcached is lighter and faster for simple workloads.

In real-world WordPress setups:

• Redis usually provides better scalability
• Memcached may consume slightly less memory

Frequently Asked Questions

Is Redis faster than Memcached?

Both are extremely fast. Memcached may be faster for simple key-value caching, but Redis offers more flexibility.

Does Redis store data permanently?

Yes, Redis can be configured with persistence.

Is Memcached outdated?

No, Memcached is still widely used but less feature-rich than Redis.

Can I use Redis and Memcached together?

Generally, you use one object caching system at a time.

Best Practices for Production Servers

• Bind service to localhost
• Secure with firewall
• Monitor memory usage
• Set memory limits
• Avoid exposing ports publicly