What Our Scanner Actually Checks and Why It Matters

When people see a score from our scanner, the first thing they ask is what it's actually measuring. It's 155 different checks. Not a handful. Not just PageSpeed. And every single one comes from what Google has publicly said matters, not guesses, not opinions. So when I say PageSpeed alone doesn't tell you much, this is why.

On the performance side, we're measuring Time to Interactive, First Contentful Paint, Speed Index, PageSpeed on both mobile and desktop, Largest Contentful Paint, Interaction to Next Paint, Cumulative Layout Shift, Time to First Byte, and server response time. Those are the Core Web Vitals plus the surrounding signals that feed into how Google evaluates user experience. They're not soft indicators — they're direct ranking inputs.

Images get a full category. We check whether the site is using modern formats like WebP or SVG, how well images are compressed, whether responsive image attributes are configured correctly, whether lazy loading is enabled, and whether alt text is actually present. Unoptimized images are one of the most common reasons a site underperforms, and it's almost always fixable.

Accessibility is in there because Google has been explicit that accessibility signals feed into how a site is evaluated. We check for alt text on images, proper labels on form inputs, accessible button text, critical blockers, and whether a language is declared on the HTML element. Stuff people consistently ignore until something goes wrong.

Security is a full sweep covering HTTPS, redirect behavior, mixed content, Content Security Policy, HSTS, X-Content-Type-Options, X-Frame-Options, Referrer-Policy, and Permissions-Policy. Google confirmed HTTPS as a ranking signal years ago, and the rest of these matter for both technical compliance and trust signals.

SEO basics that still get missed constantly. Title tag, title length, meta description, canonical tag, Open Graph data, Twitter card metadata, structured data presence, and JSON-LD validity. These aren't optional. They're the foundation of a page that's supposed to rank.

Document structure checks whether the page is built correctly at the HTML level, including DOCTYPE, valid structure, charset declaration, viewport meta, and the presence of the core HTML elements. Past that, heading structure gets its own pass. Whether an H1 is present, whether there's only one of them, and whether the heading hierarchy is logical. Multiple H1 tags on a single page is one of the most common structural mistakes we see, and it signals to Google that the page doesn't have a clear primary topic.

Crawlability covers robots.txt, sitemap.xml, and whether those files are actually accessible and configured correctly. A sitemap that exists but returns errors can actively waste crawl budget. URL integrity checks internal links, broken links, redirect loops, redirect chains, and orphan pages. A clean internal link structure helps Google understand site architecture, and redirect chains slow everything down across the board.

Indexing checks catch pages that are accidentally blocking themselves. Noindex tags, canonical signals, whether the canonical URL is itself indexable. This one surfaces more problems than most people expect. On the optimization side, we're looking at render-blocking resources, HTML minification, compression via GZIP or Brotli, browser caching, and cache header configuration. These details compound. A site that doesn't cache properly is slower on every single visit.

Mobile gets checked for responsive layout, viewport configuration, horizontal overflow, and whether navigation actually works on a phone. At this point Google indexes mobile first, so if your site doesn't work on a phone, the desktop version matters less than you think. Infrastructure checks cover HTTP/2 or HTTP/3 support and keep-alive, both of which affect speed at the server level. Then social metadata, favicon presence, console errors, and broken scripts round out the rest.

A strong PageSpeed score tells you one part of the story. A 90 on our scanner tells you the whole thing. It means the site is built correctly across performance, security, SEO, accessibility, crawlability, and structure — the full picture of what Google has said it cares about. Most sites, including ones that look polished and professional, come in well below that. Not because the design is bad. Because entire categories of signals were never addressed. The clients didn't know to ask, and the people who built the sites didn't know to check. Or they did know and just didn't do the work.

The full checklist is below. Go through it. See where your site stands. If you want the actual data instead of guessing, run it through the scanner.