How is Redis so fast as compare to other databases?

When it comes to performance and speed, Redis is often considered one of the fastest data storage systems out there. Whether you're dealing with real-time analytics, caching, or session storage, Redis performs like a champion — but why exactly is it so fast?

Let's break it down.

Unlike traditional databases (like MySQL, PostgreSQL, or MongoDB) that store data on disk (HDD/SSD), Redis stores everything in RAM. Accessing data from memory is orders of magnitude faster than reading from disk.

Redis isn’t just storing strings. It provides highly optimized data structures such as:

These structures are implemented with performance in mind — so instead of writing complex queries or doing heavy joins, you can get exactly what you need in constant or logarithmic time.