How to fix FATAL: password authentication failed for user in PostgreSQL

Double-check that you're using the correct password for the user account. Passwords are case-sensitive in PostgreSQL. If unsure, reset the password using a trusted connection.

If you have access via the OS or local socket (peer authentication), reset the password:

sudo -i -u postgres
psql

Then execute:

ALTER USER username WITH PASSWORD 'new_password';

Replace username and new_password with your values.

Locate your pg_hba.conf file (typically /etc/postgresql/VERSION/main/pg_hba.conf on Linux or %APPDATA%\\postgresql\\pg_hba.conf on Windows).

Look for entries matching your connection type (local, host, hostssl) and verify the METHOD column allows password authentication:

# Good: Allows password-based auth
host    all    all    127.0.0.1/32    md5
host    all    all    127.0.0.1/32    scram-sha-256

# Bad: Does not require password
host    all    all    127.0.0.1/32    trust

# Bad: Uses OS username instead of password
local   all    all                     peer

Rules are checked in order, so earlier matching rules take precedence.

Edit pg_hba.conf and change the METHOD field to a password-based authentication method:

- scram-sha-256 - Most secure (PostgreSQL 10+), uses SCRAM-SHA-256 hashing
- md5 - Widely compatible, uses MD5 hashing (less secure but standard)
- password - Plain text password (avoid in production)

Example configuration:

local   all             all                                     peer
host    all             all             127.0.0.1/32            scram-sha-256
host    all             all             ::1/128                 scram-sha-256
host    replication     all             127.0.0.1/32            scram-sha-256
host    replication     all             ::1/128                 scram-sha-256

After editing pg_hba.conf, reload the configuration without stopping the database:

# Linux with systemd
sudo systemctl reload postgresql

# Or using pg_ctl
pg_ctl reload -D /path/to/data/directory

# Or from psql (if you have superuser access)
SELECT pg_reload_conf();

If reload doesn't work or you need to apply other changes, restart PostgreSQL:

sudo systemctl restart postgresql

If you recently upgraded PostgreSQL (especially to v13+), check if your client supports the authentication method:

- PostgreSQL 13+ defaults to scram-sha-256
- Older clients may only support md5
- pgAdmin, DBeaver, and ORMs like Prisma usually support both

If your client doesn't support SCRAM-SHA-256, either:
- Update the client to a newer version
- Change pg_hba.conf back to md5 (less secure)
- Use a connection pooler that handles SCRAM-SHA-256 (e.g., PgBouncer)

Verify the role has the LOGIN privilege granted:

psql -U postgres

-- Check if user can login
SELECT usename, usecanlogin FROM pg_user WHERE usename = 'your_username';

-- Grant LOGIN privilege if missing
ALTER USER username WITH LOGIN;

If the above returns no rows, the user doesn't exist. Create it:

CREATE USER username WITH PASSWORD 'password' LOGIN;

After making changes, test your connection:

psql -h localhost -U username -d databasename

Or for applications, provide connection details in your connection string:

postgresql://username:password@localhost:5432/databasename

If the error persists, check PostgreSQL logs for more details:

# Linux
sudo tail -f /var/log/postgresql/postgresql.log

# Or from psql
SELECT pg_current_logfile();