What the SEO checker looks for
The checker reviews the page and supporting site files for signals that are useful when diagnosing basic SEO problems. These include the page title, meta description, main heading, canonical URL, HTTPS, mobile viewport, image alternative text and structured data, together with robots.txt and XML sitemap availability.
It also checks for llms.txt. This is a proposed convention for publishing concise, machine-readable information for language-model tools. It is not a Google ranking requirement and its presence should not be treated as evidence that a site will appear in AI-generated answers.
A page-level SEO check is only the starting point
A technically tidy page can still struggle in search if the wider site has weak internal linking, duplicated pages, poor crawl paths or content that does not answer the searcher's need. Backlinks, competing pages and the overall usefulness of the content also sit outside a simple on-page score.
Google's Search Essentials recommends helpful, reliable content, descriptive words in prominent locations and crawlable links. That is a better framework for interpreting the checker than trying to make every individual test turn green.
How to prioritise SEO checker findings
Fix issues that can prevent discovery or create ambiguity first. An unintended noindex instruction, blocked crawling, incorrect canonical or missing internal link to an important page is usually more consequential than a minor wording issue in a meta description.
Next review whether the title and H1 accurately describe what the page offers. Google recommends concise, descriptive title text and warns against keyword stuffing. Structured data should accurately represent visible page content and use a supported type where relevant.
When you need a full SEO audit
This checker examines individual pages and selected technical files. A Full SEO Audit goes wider, covering a full technical crawl, keyword and content gaps, competitor benchmarking, backlink profile review and a prioritised 90-day action plan.
For questions specifically about how content can be made easier for AI systems to discover and interpret, see AI Search Visibility and our explanation of llms.txt. Google states that its AI search features use the same foundational SEO requirements as Search and do not require special additional technical markup.