Pub/sub vs streams comparison in Redis - When to Use Which

The Big Idea

What if you could never lose a message again while still chatting live with friends?

The Scenario

Imagine you have a group chat where everyone talks at once, and you try to remember every message manually on paper.

The Problem

Writing down every message by hand is slow, easy to miss, and you can't go back to see what was said before without flipping through messy notes.

The Solution

Pub/sub lets messages flow instantly to everyone listening, while streams keep a neat, ordered history you can review anytime without losing anything.

Before vs After

✗ Before

Listen to messages and write them down manually for each user.

✓ After

Use Pub/sub to broadcast messages live; use Streams to store and read message history.

What It Enables

You can build real-time apps that deliver instant updates and keep a reliable record of all events effortlessly.

Real Life Example

A chat app where users see messages live (Pub/sub) and can scroll back to read old messages anytime (Streams).

Key Takeaways

Pub/sub is great for instant, live message delivery.

Streams store messages so you can read them later or replay them.

Choosing between them depends on whether you need history or just live updates.