What this score actually measures
This checker runs a fixed, transparent set of on-page rules against the HTML you paste in, and reports exactly which ones passed and which failed, rather than producing a single opaque number with no explanation. Each rule checks something concretely verifiable from the page's own markup: whether a title tag exists and falls in a reasonable length range, whether a meta description is present, whether the page has exactly one H1 and at least one supporting H2, whether the body content clears a rough 300-word threshold, whether every image has alt text, and whether canonical, viewport and Open Graph tags are present. If you supply a focus keyword, three more checks look at whether it appears in the title, the H1, and the body text.
Every check is weighted and summed into a percentage score, and the table beneath the summary lists every individual rule with a pass or fail badge and a short note showing exactly what was found — the actual character count of your title, the actual word count of your body text, and so on — so you can see precisely why the score landed where it did rather than treating it as a black box.
Why this is a checklist tool, not a ranking predictor
It's important to be clear about what a rule-based score like this can and can't tell you. It verifies that a set of well-established on-page basics are in place — the kind of fundamentals that are genuinely worth getting right on every page, and easy to accidentally skip on a new page built from a rushed template. It cannot evaluate the actual quality, accuracy, or usefulness of your writing, cannot account for how your page compares to competing pages actually ranking for the same query, and has no visibility into off-page factors like backlinks or overall site authority, none of which can be assessed from a single page's HTML alone.
A page can score perfectly on every rule here and still fail to rank well if the content itself is thin or doesn't genuinely answer what a searcher is looking for, and conversely a page can rank well despite missing one or two of these checks if the content is exceptional enough to outweigh it. Treat a low score as a solid, specific to-do list of easy technical fixes, and treat a high score as confirmation that the basics are covered — not as a guarantee of ranking performance.
Using the focus keyword checks effectively
The three keyword-specific checks — appearing in the title, in the H1, and somewhere in the body — reflect a long-standing, sensible practice of making sure a page's most important topic is unmistakable from its structural elements, not just buried somewhere in a paragraph. If you're auditing several pages that target different keywords, re-run the check once per page with the correct focus keyword each time, since these three checks are the only ones on this page that depend on which specific term you're optimizing for.