Understanding wp-config.php: A practical guide for WordPress configuration

Introduction to wp-config.php

wp-config.php is a critical file in WordPress. It contains the site’s database credentials and a handful of settings that control how WordPress loads and interacts with your environment.

What is wp-config.php?

The wp-config.php file is the main configuration file for WordPress. It defines constants that WordPress uses to connect to the database, locate the installation, and enable or disable features.

Core purposes

• Store database credentials: DBNAME, DBUSER, DBPASSWORD, DBHOST
• Set character set and collation: DBCHARSET, DBCOLLATE
• Define table prefix: $table_prefix
• Enable debugging and logging: WPDEBUG, WPDEBUGLOG, WPDEBUG_DISPLAY

Where is it located

You’ll find wp-config.php in the WordPress root directory. In most setups it sits alongside wp-admin, wp-content, and wp-includes. For added security, some admins move wp-config.php one directory above the web root.

Key configuration options in wp-config.php

Database settings

• define('DBNAME', 'yourdb_name');
• define('DBUSER', 'yourdb_user');
• define('DBPASSWORD', 'yourdb_password');
• define('DB_HOST', 'localhost');
• define('DB_CHARSET', 'utf8');
• define('DB_COLLATE', '');

Security keys and salts

Defines for authentication keys and salts: AUTHKEY, SECUREAUTHKEY, LOGGEDINKEY, NONCEKEY, and their corresponding salts. Generate unique values to improve security. If you don’t see them, WordPress can fill them in during installation or you can update them manually.

Debug settings

• define('WP_DEBUG', false);
• define('WPDEBUGLOG', true);
• define('WPDEBUGDISPLAY', false);

Site URL and home

• define('WP_HOME', 'https://example.com');
• define('WP_SITEURL', 'https://example.com');

Other useful constants

• define('FORCESSLADMIN', true);
• define('DISALLOWFILEEDIT', true);
• define('DISALLOWFILEMODS', true);
• define('WPALLOWREPAIR', true) // use carefully and remove when not needed

Security best practices

Move wp-config.php

Where possible, move it one directory above the web root to prevent direct access via the browser.

Permissions

Set restricted file permissions (e.g., 640 or 600) to limit access.

Keep credentials out of version control

Avoid committing wp-config.php with credentials to public repos. Use environment variables or separate config files for production.

Use secure keys and rotate

Ensure all security keys are defined and updated if you suspect compromise.

Disable file editing and mods

Set DISALLOWFILEEDIT and DISALLOWFILEMODS to true to reduce risk of unauthorized changes.

Protect with proper hosting and backups

Ensure your hosting environment is secure and keep regular backups.

Common issues and fixes

Incorrect database credentials

Double-check DBNAME, DBUSER, DBPASSWORD, and DBHOST in wp-config.php.

Database connection errors

If you see error establishing a database connection, verify credentials and that your database server is reachable.

Permissions issues

If WordPress cannot read wp-config.php, adjust file permissions.

Incorrect table prefix

Make sure $table_prefix ends with an underscore and matches your database tables.

Web server configuration

If you moved wp-config.php, ensure your server configuration allows the new path, and that ABSPATH is correctly defined.

Conclusion

wp-config.php is small but powerful: it ties WordPress to its database and defines essential behavior. Understanding its contents and keeping it secure helps improve both reliability and security of your site.