Configure file permissions for WordPress

If you have a new WordPress installation and you suddenly get the following error:

Updating failed. The response is not a valid JSON response.

This error is usually related to incorrect file ownership and permissions. To fix this, you will need to ask your hosting company to reset file permissions, but if you’re comfortable running a few terminal commands, then you can read further.

Recommended file permissions

Permissions are described in a coded 3-number format which indicate a combination of Read/Write. These are the recommended file permissions that you can set for your WordPress site: 

  • Root directory (ie. public_html/): 755
  • wp-admin: 755
  • wp-includes: 755
  • wp-content: 755
  • wp-content/themes: 755
  • wp-content/plugins: 755
  • wp-content/uploads: 755
  • .htaccess: 644
  • index.php: 644
  • wp-config.php: 640

WordPress directory and folder permissions should be set to 755, and most file permissions need to be set to 644.

Set file and folder permissions using the terminal

The web server daemon has to be run under a specific user. On NIX-based systems, the default is usually the www-data user. The web server can access any file that www-data can access. It has no other importance.

Use the following commands to give the www-data user and www-data group access to your WordPress installation (please replace /var/www/html/ with the correct path to your website):

sudo chown -R www-data:www-data /var/www/html/

Set the permissions for all directories to 775

sudo find /var/www/html/ -type d -exec chmod 775 {} \;

Set permissions for all files to 664

sudo find /var/www/html/ -type f -exec chmod 664 {} \;

Create an empty .htaccess file in the root of your website direct using the touch command:

touch /var/www/html/

Change ownership of .htaccess to 666:

chmod -v 666 /var/www/html/

Then head into the WordPress Admin > Settings > Permalinks and click Save Changes. These settings are then saved to the .htaccess file.

That’s it, you’re done!