Understanding the 200+ SEO checks
Every check we run, grouped by category, with the rationale and the typical fix.
Each audited URL is graded against 200+ checks across six categories. This page lists the categories and the highest-impact checks in each. The full machine-readable catalog is available at /api/checks (authenticated).
Categories
| Technical | ~60 checks. HTTP status, redirects, indexability, sitemap consistency, canonical correctness. |
| On-page | ~50 checks. Title, meta description, headings, image alt, internal anchor text. |
| Content | ~30 checks. Length, uniqueness, reading level, keyword targeting, AI-readability. |
| Core Web Vitals | ~15 checks. LCP, INP, CLS, FCP, TTFB, image sizing, layout stability. |
| Links | ~25 checks. Broken links, orphan pages, internal link distribution, nofollow correctness. |
| Structured data | ~20 checks. JSON-LD validity, recommended schemas per page type, breadcrumbs, FAQ. |
Severity levels
| Critical | Likely costing you traffic right now. Fix first. |
| Warning | Best-practice misses. Won't tank rankings but compound with other issues. |
| Info | Opportunities and observations. Not always fixable; sometimes intentional. |
Highest-impact Technical checks
- Missing or wrong canonical tag.
- Page returns 4xx or 5xx.
- Page is noindex but linked from indexable pages.
- Sitemap missing pages we crawled.
- Mixed-content (HTTPS page loading HTTP resources).
- Redirect chain longer than 3 hops.
- TLS cert expired or mismatched.
Highest-impact On-page checks
- Missing or duplicate <title>.
- Title under 30 or over 60 characters.
- Missing meta description.
- No H1 or multiple H1s.
- Heading hierarchy skipped levels (e.g. H1 → H3).
- Image missing alt attribute.
- Internal link with generic anchor ("click here", "read more").
Highest-impact Core Web Vitals checks
- LCP > 2.5s (field data preferred).
- INP > 200ms.
- CLS > 0.1.
- Image without width/height attributes (causes layout shift).
- Render-blocking JS in the critical path.
AI-readability checks (newer)
- Heading hierarchy clarity.
- Answer-shaped paragraphs (paragraphs starting with a direct answer).
- Schema markup (FAQ, HowTo, Article).
- Citation-worthy specifics (numbers, dates, named sources).
Where each check is documented
In the audit report, every issue links to its own check page with the exact rule, the rationale, examples, and the recommended fix. The URL pattern is `/checks/{check_id}`.
Custom checks (CEO plan)
CEO plan supports custom checks defined in JS. A check receives the rendered HTML and metadata and returns pass/fail/warning with an optional message. See API & integrations → Custom checks for the SDK.
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