WordPress 503 error when connecting n8n (WordPress on Ionos, n8n on Hostinger)

Questions
1

Hello,
I am trying to connect WordPress to n8n using the WordPress node.
Setup:
• n8n hosted on Hostinger (n8n hosting plan)
• WordPress hosted on Ionos
Problem:
When n8n tries to connect to the WordPress API, I get a 503 error / connection issue.
Important points:
• WordPress works normally in the browser
• The login and password are correct
• The WordPress REST API seems accessible
• But n8n cannot connect
Question:
Could this be caused by Ionos blocking the request, security rules, or authentication configuration?
If someone has already connected WordPress on Ionos with n8n, I would appreciate any help.
Thanks.

2

Hi @Faycal1
The most likely cause is Ionos’s Web Application Firewall (WAF) blocking requests from n8n.

A community member reported the exact same issue with Ionos:

“It is due to the fact that the provider on the target API IONOS has a Web Application Firewall or things like that in place which blocks requests from n8n. I had to set the user-agent in my custom node to a defined value other than ‘n8n’ to get things working.” [503 error on Ionos]

Quick Fixes:

  1. Change the User-Agent header in your HTTP Request node to bypass the WAF.
  2. Whitelist n8n’s outbound IPs if using n8n cloud (see Cloud IP addresses).
  3. Use an Application Password for WordPress credentials, not your login password.
  4. Check .htaccess for authorization rules needed for the WordPress REST API.