---
title: "Domain health check (PRO)"
date: 2026-09-12
author: "Claude MCP"
---

# Domain health check (PRO)

Domains break quietly. A certificate expires, a DNS record is changed, a www variant stops redirecting, and the first sign is a drop in traffic weeks later. The *Check domains* button on the plugin's settings screen tests every domain you saved and tells you what is wrong in one table.

 
## How to use it

 Open the plugin, press **Check domains** and wait a few seconds. The check uses the domains as they are saved, so save your changes first. Every row gets a status - OK, a warning or an error - with one sentence of explanation.

 
## What is checked, per domain

 
- **DNS** - the domain resolves, and the addresses it resolves to are shown.
- **HTTPS** - the domain reaches *this* Joomla site. The check asks the domain a question only this site can answer correctly, so a domain that points at another server or another Joomla is caught.
- **Certificate** - valid for this name, with a warning when it expires within two weeks and an error when it has expired.
- **HTTP to HTTPS** - the plain http address redirects to https.
- **www variant** - the variant you did not configure redirects to the one you did. A variant that does not resolve at all is fine and says so.
- **robots.txt** - the domain serves the robots.txt you filled in for it, if you filled one in.

 
## What is checked once, for the whole site

 
- **Sessions** - sessions are stored in the database, which is what makes logging out work on every domain.
- **Language filter** - the core plugin Domain per Language depends on is enabled.
- **SEF URLs** - search engine friendly URLs are on.

 
## Not reachable from the server

 Some hosting setups cannot reach their own public address: the server asks for your domain, the request goes out and never comes back. The check then says *not reachable from the server* and offers a link to open the test in your own browser. A 64-character code in that page means the domain does reach this site and only the server itself cannot see it. That is a hosting matter, not a plugin one; your visitors are not affected.

 
## Safety

 The check runs only for administrators who may manage plugins, and only against the domains you saved: it never sends a request to a host taken from the browser. Every connection has a five second time-out, and redirects are not followed, so a chain of redirects cannot hide a problem.