Every check, and the fix for it.

Whether a crawler can find, follow and index the site at all. These are the highest-severity checks in the set: a leftover noindex or a robots.txt that disallows everything makes every other finding irrelevant.

What a search result actually shows. Titles and descriptions are per page, and the failure mode is almost always one value set in a layout and never overridden per route.

Whether answer engines can reach your content, read it without JavaScript, and quote it once they have. This is the group no classic SEO tool covers, and the one where the fixes are cheapest relative to what they change.

What your link looks like when somebody shares it. Every failure here is silent — the card renders wrong on somebody else's screen and nobody tells you.

The markup that makes a result eligible for anything beyond a blue link, and increasingly how an answer engine decides what your product is.

Presence and reachability of the legal pages, and whether tracking fires before consent. 13x detects; it does not give legal advice and does not generate legal text.

The defects that make a page unusable with a screen reader or a keyboard, plus the European Accessibility Act statement obligation that has applied since June 2025.

Read from response headers and markup already fetched — never by probing. These are one-line changes with no downside, which is why their absence is usually an oversight rather than a decision.

Causes rather than guessed metrics: what is blocking the render, what is uncompressed, what is shifting the layout. Every one is measured from the response, not estimated from a score.

Whether a visitor who is convinced can act, and whether you would know if they were not. Advisory rather than scored hard — several of these are legitimate choices.

SPF, DKIM, DMARC and MX, read from DNS. The answers are definitive rather than heuristic: either the record is there or it is not. You launch, you send a welcome email, it lands in spam — and nothing tells you.

Transport and domain health. Nothing above matters if the certificate expired this morning or the registration lapses next month.