Free tool
Everything at once: registration and how long you have held it, certificate lineage from public logs, mail records, subdomains, hosting and third-party scripts. Every finding shown in full. No account, no card, no limit on how often you run it.
About ten seconds, and every finding is shown in full. Nothing that needs attention is ever held back for a paying plan.
How to read it
Most checkers open with a list of faults. That works if you already know what you have. If you do not — and most people do not — a list of faults about things you have never heard of is not much help.
Holdings is the inventory: what exists, who controls it, when it renews, what your pages load. It is worth reading even when nothing is wrong, and for a lot of people it is the first time any of it has been written down.
Needs attention is ordered by how likely you are to be surprised, not by how alarming it sounds. A certificate expiring next month is real, but you probably know about it. A staging site that has been public for two years is the one nobody mentioned, so it comes first.
Every item links to the actual steps for your registrar, host or mail provider. Those are free as well. Nothing here is a preview of something you have to buy.
It tells you where things stand right now. Run it again next month and it will tell you about next month, remembering nothing about today.
Every free checker works this way, including the well known ones. The catch is that the questions people actually get asked are about the past. When did the host change. What did that record say before somebody edited it. Has any of this been looked after, and since when.
None of that can be worked out later. It has to have been kept at the time, which is the difference between running a check and keeping a record — and the reason the second one costs $15 a month.
Free, unlimited, and every finding shown in full.