Redis stands for “remote dictionary server.”

It’s an in-memory NoSQL database server — there aren’t tables, columns, or rows.

In other words, Redis is a simple key/value database.

To execute the Redis client from the command line: redis-cli

To execute the Redis server from the command line: redis-server

apt install redis // for ubuntu

brew install redis // for macos

redis-cli commands:

ECHO “<message>”

PING // returns PONG

SET key “value” // sets value of key

GET key // returns value of key

SETNX key “value” // set if the key does not exist; returns 0 if it didn’t set; returns 1 if it did set

GETRANGE key start-value end-value, e.g. getrange name 0 0 // returns first character of a string

SETRANGE name 5 “us” // updates from position 5

MGET key1 key2 key3 // returns value for each key; if one doesn’t exist, “nil” is returned

MSET key1 “value1” key2 “value2” // and on and on — as many key/value pairs as you want

DEL key1 // the number that’s returned is the number of keys deleted

KEYS * // lists all keys in the Redis database

FLUSHALL // deletes all keys

Redis convention for keys: blog:post-id:comment-id

EXPIRE key <seconds>, e.g. expire name 60

TTL key // determine how many seconds remain for the expiring key

SETEX key <seconds> “value” // set a key with a value and an expiration in a single statement

To install Redis for node.js: npm install ioredis

Simple use case on node.js:

const Redis = require(‘ioredis’);

const redis = new Redis({
host: ‘’,
port: 6379

(async () => {
const value = await redis.set(‘key1’, ‘value1’);