Jun 3, 2026 · Databases · 1min read

redis://localhost:6379 — Connect & Run Redis Locally

What does redis://localhost:6379 mean? URI formats, redis-cli, Docker, and Connection refused fixes.

redis://localhost:6379, redis localhost, or REDIS_URL=redis://localhost:6379 means your app expects Redis on this machine (default port 6379). It is a connection string, not a browser URL.

Connection string cheat sheet

Use	URI / config
Default (no password)	`redis://localhost:6379`
DB index	`redis://localhost:6379/0`
With password	`redis://:password@localhost:6379/0`
Env var	`REDIS_URL=redis://localhost:6379`

Also: redis_url=redis://localhost:6379. Port guide: localhost ports §6379.

Verify with a client

redis-cli -u redis://localhost:6379 ping
# PONG

redis-cli
SET user:1 "Alice"
GET user:1

const Redis = require('ioredis');
const redis = new Redis(process.env.REDIS_URL || 'redis://localhost:6379');

Typical uses: API cache, sessions, Bull/BullMQ queues, rate limiting.

Install & start

macOS: brew install redis → brew services start redis

Docker:

docker run -d --name redis -p 6379:6379 redis:7

Compose: map 6379:6379, set REDIS_URL=redis://localhost:6379 on the host (use hostname redis between containers).

Troubleshooting

ECONNREFUSED 127.0.0.1:6379 — start Redis; check lsof -i :6379.
NOAUTH — include password in the URI.
Port busy — map 6380:6379 and update the URI.
Do not expose passwordless Redis on 0.0.0.0 to the public internet.

See port-conflicts, MongoDB.

Summary

redis://localhost:6379 = local Redis default. Confirm with redis-cli ping, then set REDIS_URL.