This means the Redis instance requires a password but your client connected without one. Supplying the correct credentials resolves it. Jump to your situation below or work through the methods in order.
The Redis NOAUTH Authentication required error means the instance is protected with a password (the requirepass setting, or an ACL user) but your client connected without supplying credentials, so Redis refuses commands until you authenticate. The fix is to provide the password: send AUTH password right after connecting, or set the password in your client library's connection configuration so it authenticates automatically. With Redis 6 and later ACLs you may also need a username, using AUTH username password. The password must match what is configured on the server in requirepass or the ACL. Storing the credential securely (an environment variable or secret, not hard-coded) keeps it both working and safe. Once the client authenticates, commands are accepted.
When requirepass or an ACL is set, Redis treats every new connection as unauthenticated and rejects commands with NOAUTH until the client proves who it is. It is a security gate, not a fault: the server is doing exactly what it was configured to do.
So the fix is to authenticate. Either issue AUTH after connecting, or, better, configure the password in the client so every connection authenticates automatically. With ACL users you supply a username too. The credential simply has to match the server's configuration.
“NOAUTH is just a locked door, Redis has a password and your client knocked without the key. The quick test is AUTH right after you connect, but the real fix is to put the password into the client's connection config so every connection authenticates on its own. On Redis 6 and up with ACLs you also pass a username. And please pull that password from an environment variable or a secret store, not a string baked into the code.”
AUTH yourpassword
AUTH username password.CONFIG GET requirepass from an authenticated session.ACL WHOAMI ACL LIST
NOAUTH means the instance needs a password and the client did not send one. Authenticate with AUTH right after connecting, or set the password in the client config so it happens automatically. With ACLs, include the username. Make sure the credential matches the server and is stored securely.
If the password is correct but NOAUTH persists, you may be hitting a different instance than you think, or a proxy is stripping the AUTH; confirm the host and port and test with redis-cli -a from the app server. You can also submit your error to us for a tailored fix.