What is a website SEO check?

A website SEO check is an automated audit that examines your site for the technical factors that affect search rankings: page speed, indexability, meta tags, structured data, mobile usability, broken links and more. It produces a health score and a list of specific problems, each with a recommended fix.

What does it actually check?

A thorough SEO check measures everything a search engine sees when it visits your page. That means load speed, how the page renders on phones, whether the crawler can reach it, whether your title tags and headings match your content, and whether you have structured data that tells machines what your business is.

In practice the findings fall into four groups, and it is worth knowing which is which, because they fail for different reasons and are fixed by different people:

Performance. Core Web Vitals — Largest Contentful Paint, Cumulative Layout Shift and Interaction to Next Paint — plus the things that cause them: oversized images, blocking scripts, a slow first response from the server. This is usually a developer fix, and it is usually the slowest to land.
Indexability. Whether Google is permitted and able to include the page at all: HTTP status, robots directives, canonical tags, redirect chains. A page failing here scores zero on everything else, because nothing else can matter.
On-page signals. Titles, meta descriptions, heading structure, link text, image alt text, thin or duplicated content. Mostly an editorial fix, and mostly the cheapest wins on the list.
Machine readability. Structured data, Open Graph tags, and whether AI assistants are allowed to fetch the page at all. Increasingly this decides whether you get quoted in an AI answer rather than merely ranked in a list of links.

The goal is not a vanity score. The goal is a list of concrete problems you can fix: images that are too large, meta descriptions that are missing, links that are broken, schema that is malformed. Each one loses you traffic, and each one has a solution.

Checking one page versus checking a whole site

These are different jobs, and conflating them is the most common reason an SEO check misses the thing that was actually wrong. A single-page check tells you about the URL you gave it. A site-wide crawl tells you about patterns — and some of the most damaging problems only exist as patterns.

Duplicate title tags are the clearest example. A title is only duplicated relative to some other page, so no single-page tool can possibly find one; it will report your title as present, the correct length, and perfectly fine. The same is true of orphan pages, internal redirect chains and cannibalised keywords. If you have ever run a page through three different checkers, got three green results, and still watched the page fail to rank, this is very often why.

The practical rule: crawl the site when you want to know what is wrong, and check a single page when you already know what you are looking for and want a fast answer. Our free single-purpose tools cover the second case — for instance the indexability checker when a page is missing from Google, or the meta tag checker when a shared link is not unfurling properly.

Why run one at all?

Because most sites have issues their owners do not know about. A redirect chain from an old URL. A broken link Google keeps hitting. A mobile layout that cuts off the CTA. Schema that was supposed to go live but never made it into the build. These are the quiet killers — individually minor, together enough to signal that the site is unmaintained, and rankings drift down.

An SEO check surfaces the stack. You fix the critical issues first, the site recovers, and then you keep it there by catching new issues monthly before they compound.

What an SEO check cannot tell you

Worth saying plainly, because a lot of tools imply otherwise. An automated check reads what is on the page. It cannot judge whether your content is actually the best answer to the query, and that judgment is the largest single input into where you rank. It cannot see your backlinks, your brand searches, or how people behave after they click.

It also cannot promise a ranking. A perfect score removes the technical obstacles working against you; it does not create demand for your page. Any checker that presents a score as a predicted position is selling you something. The honest framing is narrower and more useful: this is the list of things a machine can verify are wrong, so you can stop losing on those and compete on the parts that need a human.

How to read the score

Treat the number as a triage device, not a grade. What matters is the severity ordering underneath it: one critical indexability failure is worth more of your attention than a dozen missing alt attributes, even though the dozen moves the score further. A site at 70 with no critical issues is in better shape than a site at 85 with one page silently carrying a noindex tag.

Compare against yourself over time rather than against competitors. Scores are not standardized between tools — every vendor weights categories differently — so a 78 here and a 92 elsewhere are not in conflict and neither is wrong. What counts as a good SEO score goes into the bands in more detail.

How often should you run one?

After any major change — a redesign, a migration, new pages — and at least monthly on an actively maintained site. Problems build up between checks, and the earlier you catch them the cheaper they are to fix.

Migrations deserve special mention: run a check immediately before and immediately after, and compare. Most catastrophic SEO losses are not gradual declines but a single deployment that changed a robots rule, dropped a canonical, or moved every URL without redirects. Those are trivial to spot within a day and expensive to discover a month later, once Google has recrawled and dropped the pages.