About SiteCheckTools
A set of free technical checks for people who run websites, built around a single constraint: never show a number that was not actually measured.
What this is
Every tool here does one thing. It takes a domain or a URL, performs a real lookup against a public data source, and shows you what came back — the value, what it means, and the threshold it was judged against. Then it prints the raw exchange underneath so you can check the working.
There are no accounts, no email gates, no trials, and no saved reports. You arrive with a question, you get an answer, you leave. That is the entire product.
Why build it this way
Most free web tools are lead-generation forms wearing a tool costume. They take your URL, show you a score with no stated methodology, colour it red, and put a signup button under it. The score is unfalsifiable by design, because a number you cannot verify cannot be argued with.
The alternative is to show your work. If a page reports that four resolvers were queried, it prints all four answers and their response times. If one of them failed, it says so instead of quietly reporting three. If a registry redacted a record, the redaction is shown as a redaction rather than papered over with a stale copy from somewhere else.
That approach costs traffic in the short term — an honest “this check failed” converts worse than a confident wrong answer. It is the right trade anyway, because the entire value of a diagnostic tool is that you can act on what it tells you.
Who it is for
People who already know what a nameserver is, and need to find out why theirs is misconfigured. Developers mid-migration, agencies checking a client’s handover, site owners who woke up to an expired certificate.
The pages are written for that reader: dense, specific, no preamble. Where a tool has a limitation, it is stated next to the result it affects rather than hidden in a footer.
How it is funded
Affiliate commissions on hosting and domain registration. When a result identifies a problem one of those products actually solves, the page may suggest one and we earn a commission if you buy.
The safeguards are structural rather than promised. A suggestion cannot render without a specific finding attached to it, so there is nothing to show on page load or after a clean result. Every suggestion states the problem before it names a product. And the measurement code has no knowledge of which partners exist, so there is no path by which a commission could influence a number. Full terms are in the affiliate disclosure.
The standards this site holds itself to
- Nothing is estimated. A failed lookup produces an error that names the failure, never a plausible-looking number.
- Every result shows its source. The transcript under each result is the raw exchange, reproducible with standard command-line tools.
- Commercial links are triggered by findings, never by visits. No finding, no suggestion.
- The site meets the standard it measures. It would be absurd to run a slow site that grades other people’s speed, so there is no render-blocking JavaScript, no web fonts, and no layout shift when results arrive.
- Limitations are published. What each tool cannot see is written on its page, not discovered by you later.
Getting in touch
Corrections are the most useful thing you can send. If a result here disagrees with one you trust, the transcript should show exactly where the two diverge — send it to hello@sitechecktools.com and it will be looked at. Feature requests and bug reports go to the same address, or see the contact page.
The full methodology behind every number is documented on how we measure.