How to fix Invalid password in PostgreSQL

Double-check that you're using the exact password set when the user account was created. PostgreSQL passwords are case-sensitive.

Try connecting with psql directly:

psql -U postgres -h localhost -d postgres

If prompted, enter your password carefully. If this works, the issue may be with how your application passes the password.

If your password contains special characters (@, :, %, $, #, etc.), they must be percent-encoded in connection URLs.

For example, if your password is my@pass:123, encode it as my%40pass%3A123:

# Wrong - @ and : will break the URL parsing
psql "postgresql://user:my@pass:123@localhost:5432/mydb"

# Correct - special characters encoded
psql "postgresql://user:my%40pass%3A123@localhost:5432/mydb"

Or use the connection parameters approach instead:

psql -h localhost -U user -d mydb -W

This prompts for password without URL parsing issues.

If the user was created without a password, you'll get an authentication failure. Connect as a superuser and set the password:

sudo su - postgres
psql

Then set or reset the password:

ALTER ROLE username WITH PASSWORD 'new_password';
ALTER ROLE username LOGIN;
\q

Test the connection:

psql -U username -h localhost -d postgres -W

PostgreSQL uses pg_hba.conf to determine how clients authenticate. If it's set to peer or ident, password authentication is bypassed.

Locate pg_hba.conf (usually in /etc/postgresql/{version}/main/ on Linux or %AppData%\PostgreSQL\{version}\pg_hba.conf on Windows):

sudo cat /etc/postgresql/15/main/pg_hba.conf | grep -v "^#"

Look for lines like:

# TYPE  DATABASE        USER            ADDRESS                 METHOD
local   all             all                                     peer
host    all             all             127.0.0.1/32            md5
host    all             all             ::1/128                 md5

If you see peer for local connections, change to md5 or scram-sha-256:

local   all             all                                     scram-sha-256

Save the file and restart PostgreSQL:

sudo systemctl restart postgresql

PostgreSQL 10+ defaults to SCRAM-SHA-256, but older clients may only support MD5. Check your client library version.

If using Docker, DBeaver, or pgAdmin, ensure they're updated:

# Python
pip install --upgrade psycopg2-binary

# Node.js
npm install --upgrade pg

# Ruby
gem update pg

If you must support legacy clients, modify pg_hba.conf to use MD5 (less secure):

host    all             all             127.0.0.1/32            md5

Then restart PostgreSQL.

After any pg_hba.conf changes, PostgreSQL must be restarted for changes to take effect.

On Linux (systemd):

sudo systemctl restart postgresql

On Linux (older systems):

sudo service postgresql restart

On macOS (Homebrew):

brew services restart postgresql

On Windows (Services):
1. Press Win+R, type services.msc
2. Find "postgresql-x64-{version}" and right-click → Restart

Verify it's running:

sudo systemctl status postgresql