About

About IncogSay

39 free tools · no accounts · nothing you enter is stored

What IncogSay is

IncogSay is a small, independent site that publishes free online tools. There are 39 of them today, grouped into 3 areas, and every one has its own page with its own explanation — nothing is hidden behind a sign-up, a trial or a paywall.

  • Email Suite11 tools— Email authentication & deliverability.
  • Link & URL10 tools— Links, redirects & certificates.
  • Calculators18 tools— Dates, time, grades, trades & networks.

The list is not fixed. We add a tool when there is a job people keep doing by hand, and a new area when there are enough of those jobs to make a group. The site is built so that adding either is a small change rather than a rebuild.

How the tools run

The calculators are plain JavaScript in the page. The dates you type are never sent anywhere, because there is nowhere for them to go — the arithmetic happens on your own machine, and the tool keeps working if you lose your connection halfway through.

The lookup tools need to reach the public internet, so they call a worker running at the network edge. It performs the DNS query, the TLS handshake or the HTTP request, builds the answer in memory and returns it. When the response is sent, that memory is gone: the domains, URLs, QR images, passwords and headers you submit are not written to a database, a log file or a tracking cookie, and there are no accounts to attach them to.

The one deliberate exception is clearly marked. Some link checks can consult public reputation feeds, which necessarily means sending the URL to those third parties — so that is an opt-in checkbox, off by default, never automatic.

How we check the tools are right

A tool is only worth using if its answer can be trusted, so each one is written against the document that defines the thing it measures, and cites it on its own page:

  • Email — SPF against RFC 7208, including the 10-lookup limit that most broken records fall foul of; DKIM against RFC 6376; DMARC against RFC 7489; MTA-STS and TLS-RPT against RFC 8461 and RFC 8460; header parsing against RFC 5322; BIMI against the current draft specification and the SVG Tiny P/S profile mailbox providers require.
  • Links — registration dates come from ICANN's RDAP service rather than a scraped WHOIS page; certificate details come from a live TLS handshake, not a cached report; redirects are followed hop by hop and reported with the status code each server actually returned.
  • Calculators — the date engine is covered by an automated test suite that runs on every change, including the awkward cases: leap days, month ends, negative spans and the difference between the two counting conventions people expect.

Where a result is a judgement rather than a fact, we say so and show the working. Risk scores come with the signals that produced them, DNS answers come with the raw record, and every calculator states which counting convention it used — so you can check the reasoning instead of taking the number on faith.

The limits are real and worth stating plainly. A lookup only sees what is published publicly at that moment; DNS answers can be cached upstream; a clean result means nothing was found by these checks, not that something is safe. Anything consequential should be confirmed against the authoritative source, and if you find a result you believe is wrong, tell us — that is how most of these edge cases got fixed.

What we deliberately do not do

  • No accounts, no email address, no sign-up wall in front of a result.
  • No selling, sharing or brokering of the values you enter — they are not kept, so there is nothing to sell.
  • No claim that a clean result makes something safe, and no professional advice. The calculators are arithmetic aids, not clinical or legal assessments — the disclaimer spells this out.
  • No affiliation with the brands that appear in examples. Google, Microsoft, Yahoo and the rest are named because their records are public and useful to demonstrate on.

Who builds it

IncogSay is built and maintained by a small independent team of engineers and administrators — people who got tired of pasting a domain into a site that wanted an account first, or of doing the same date arithmetic in a spreadsheet every quarter. The site is funded by advertising, which is why the tools can stay free and why none of them need your data.

Corrections, bug reports and requests for the next tool are genuinely welcome: get in touch. If you want the technical detail of what runs where, how it works walks through it, and the architecture notes go further.