Introducing the Rule Engine

Every SEO tool shows you data. Most leave the interpretation to you.

SERP Lens now runs 146 individual SEO rules against every page you visit: titles, meta descriptions, canonicals, hreflang, headings, security headers, performance, links, images, and more. Results surface in a new overview panel, grouped by severity: critical, high, medium, low, info.

No export. No waiting. Analysis happens as you browse.

Why a rule engine

The previous analysis pipeline in SERP Lens extracted data and displayed it. Useful, but you still had to scan each panel and decide what mattered. The rule engine inverts that, it evaluates the data against known SEO best practices and surfaces what needs attention.

Think of it as a technical audit that runs on every page load. Except it's instant, and it lives inside your browser.

What it covers

18 rule categories, each with specific checks:

On-page: Title tag length, duplicates, keyword placement. Meta description length and duplication. H1 presence, hierarchy, nesting. Image alt text, file sizes, lazy loading. Content word count, readability, lorem ipsum detection.

Indexing: Canonical conflicts between HTML and HTTP headers. Self-referencing canonicals. Relative canonical URLs. Hreflang consistency, missing self-references, conflicting x-default values. Robots directives — noindex in meta tags, X-Robots headers, unavailable-after dates.

Links and URLs: URL structure issues: uppercase characters, underscores, excessive parameters, tracking params, repetitive paths, non-ASCII characters. Internal and external link validation. Pagination rel=prev/next checks.

Security: HTTPS enforcement. Mixed content. Missing HSTS, CSP, X-Content-Type-Options, X-Frame-Options, Referrer-Policy. Insecure form actions. Protocol-relative URLs. Unsafe cross-origin targets.

Performance: Slow server response. Large HTML and total page size. Render-blocking resources. Missing compression. Unminified CSS and JS. Unused CSS. Excessive DOM depth. Missing cache policies. Missing image dimensions.

JavaScript: JS rendering checks, framework detection, client-side rendering issues.

Structured data: Coming soon. Validation for JSON-LD, rich result errors and warnings, and missing schema markup.

How it works

Each rule is a self-contained check with an ID, severity level, category, and a specific recommendation. The engine registers all rules and evaluates them against the page data SERP Lens already extracts — HTML source, HTTP headers, DOM state, response metadata.

The overview panel groups results into on-page, indexing, and crawling sections. Each section shows a count of issues found and expands into specific alerts with severity badges and actionable recommendations.

The detail that matters

Every rule includes a recommendation — not "fix this" but a specific explanation of what to change and why. A canonical mismatch rule doesn't tell you "canonical issue detected." It tells you the canonical is defined in both the HTML and HTTP header, which creates conflicting signals, and recommends using one source.

This is the difference between data and analysis. The rule engine does the interpretation.

What's next

More rules are coming. Structured data validation is in development, along with additional checks across every existing category.

Rules are configurable. Thresholds like title length limits or page size warnings can be adjusted to match your standards or your client's requirements.

The rule engine is available now. Update to the latest version and open the overview panel on any page.