Domains break quietly. A certificate runs out, somebody changes a DNS record, a www version stops redirecting. The first thing you notice is a drop in visitors, weeks later.

The Check domains button on the plugin's settings screen tests every domain you saved and puts the result 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 that explains it.

What is checked for every domain

• DNS - the domain is found, and you see which server addresses it points to.
• HTTPS - the domain really reaches this Joomla site. The check asks the domain a question that only this site can answer correctly, so a domain that points at another server, or at another Joomla, is caught.
• Certificate - the certificate is valid for this name. You get a warning when it runs out within two weeks, and an error when it has already run out.
• HTTP to HTTPS - the plain http address sends visitors on to https.
• www version - the version you did not configure redirects to the one you did. A version that does not exist in DNS at all is fine, and the check says so.
• robots.txt - the domain shows the robots.txt you filled in for it, if you filled one in.

What is checked once, for the whole site

• Sessions - your sessions are stored in the database. That is what makes logging out work on all your domains at once.
• Language filter - the core plugin that Domain per Language needs is switched on.
• SEF URLs - search engine friendly URLs are switched on.

"Not reachable from the server"

Some hosting setups cannot reach their own public address. The server asks for your own domain, the request goes out, and it never comes back.

The check then says not reachable from the server and gives you a link to run the test in your own browser instead. If you see a 64-character code on that page, the domain does reach this site, and only the server itself cannot see it.

That is something for your hosting company, not for the plugin. Your visitors notice nothing.

Is it safe?

The check only runs for administrators who are allowed to manage plugins, and only against the domains you saved. It never sends a request to a domain that came from the browser.

Every connection gives up after five seconds, and redirects are not followed, so a chain of redirects cannot hide a problem from you.