A Cloudflare Error 1003 occurs when a user tries to access a website by typing Cloudflare’s shared numeric IP address directly into their web browser address bar instead of using the website’s domain name.
Common causes
A client attempted to access a website by entering one of Cloudflare’s public IP addresses directly into their web browser address bar (e.g. http://104.16.x.x) instead of using the website’s domain name.
Because Cloudflare is a reverse proxy that hosts millions of websites across shared Anycast IP addresses, Cloudflare relies on the HTTP Host header to know which website you want to view. When you enter a raw IP address, Cloudflare has no way to determine which website to load.
Resolution
If you are a visitor
- Type the full domain name (e.g.
https://example.com) into your browser instead of entering a raw numeric IP address.
If you are the website owner
- If you want visitors to access your server via its direct IP, you must bypass Cloudflare and configure your origin server’s default virtual host to answer on port 80/443 directly.
Source: Cloudflare Documentation - Troubleshooting Cloudflare 1XXX errors (Error 1003)