Devs-Fix | Quick Solutions for Real-World Code Errors

psql: FATAL: password authentication failed for user means the PostgreSQL server received your connection, looked up the role you asked for, compared the password you sent against the stored verifier, and rejected the match. The connection itself worked — TCP opened, TLS negotiated, the startup packet was parsed — so psql: FATAL: password authentication failed for user is never a networking problem, and chasing firewalls will waste your afternoon. The deceptive part is that the server prints the same message for a wrong password, a role that does not exist, a role with no password set at all , and a password that exists but was hashed with an algorithm your client cannot speak. That is deliberate: PostgreSQL refuses to tell an anonymous caller which of those is true. This page gives you the fastest fix first, then ten distinct causes ordered by how often they actually bite in production, then a checklist for the case where none of them match. Every cause includes the command that r...