Redis Connection String Format

Redis URI Format

Redis connection strings use the redis:// scheme (or rediss:// for TLS-encrypted connections):

redis://[user:password@]host[:port][/database]
rediss://[user:password@]host[:port][/database]

Default Values

Parameter	Default
Host	localhost
Port	6379
Database	0
Username	(none)
Password	(none)

Database Numbers

Unlike SQL databases that use names, Redis uses numbered databases from 0 to 15 (default configuration). The database number is specified as the path component:

redis://localhost:6379/0   # Default database
redis://localhost:6379/1   # Database 1
redis://localhost:6379/5   # Database 5

Authentication

Redis 5 and earlier only uses password authentication (no username):

redis://:mysecretpassword@localhost:6379/0

Note the colon before the password — the username is empty.

Redis 6+ (ACL) supports username + password via the ACL system:

redis://myuser:mypassword@localhost:6379/0

TLS / SSL Connections

For encrypted connections (common with Redis Cloud, ElastiCache, Upstash), use the rediss:// scheme (note the double 's'):

rediss://default:token@redis.example.com:6380/0

Sentinel and Cluster

Redis Sentinel and Cluster deployments use additional parameters that vary by client library. For example, with ioredis in Node.js:

// Sentinel
{
  sentinels: [{ host: "sentinel1", port: 26379 }],
  name: "mymaster",
  password: "secret"
}

These configurations typically use object-based config rather than URI strings, as the URI format does not standardize Sentinel/Cluster parameters.