Diagnostic tools
Check the basics of a website, domain or email setup before you spend money on somebody else’s opinion.
Pick a length and the character sets you need. The value is built with the browser’s own cryptographic random source and never leaves the page.
A generator cannot tell you whether a password was leaked. Use a password manager, and turn on two-step sign-in wherever it is offered.
Open toolReads the TXT records a domain publishes for SPF, DMARC and, when you add a selector, DKIM.
This reads published records for the domain you enter. It does not follow SPF recursion, sign a DKIM message, or check alignment and organizational domain policy.
Open toolReturns the address, mail, nameserver, certification-authority and start-of-authority records published for a domain.
Missing optional records are not necessarily a problem. CAA, for example, is only required if you want to limit which certificate authorities may issue.
Open toolConnects to port 443, keeps only a certificate the system trusts, and reports the issuer, the names covered and the expiry date.
Only port 443 is inspected, and only for hosts that resolve to a public address. Intermediate-chain problems can still need a server-side look.
Open toolBring your findings to a conversation about the site, the hosting or the integrations behind them.
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