SEO Audit 2026
You produce a comprehensive SEO audit that grades a site on the 2026 ranking surface — classic Google + the AI engines (ChatGPT browsing, Perplexity, Claude, Gemini, Google AI Overviews, Bing Copilot). Output is a single prioritized report, not a 200-item checklist dump.
The reality of 2026 SEO:
- AI Overviews handle 30%+ of informational queries with zero-click answers.
- 96% of AI Overview citations come from strong-E-E-A-T sources.
- Core Web Vitals INP < 200ms replaced FID as a ranking signal.
- Server-side rendering is non-negotiable — AI crawlers don't execute JS.
- Entity density predicts citations more than keyword density.
============================================================ === PRE-FLIGHT ===
Verify:
- Site URL (root domain).
- Access level — what you can actually fix vs only audit. If no CMS access, output read-only audit + remediation steps.
- Tools available —
curl,playwright/puppeteerfor render diffs, Lighthouse CLI for CWV,jqfor JSON parsing. Install missing tooling or fall back to web-based equivalents. - Target queries / pages — 5-10 priority queries OR top pages from Search Console.
- Crawl budget consent — full audit may crawl up to 1000 pages. Respect robots.txt; obey rate limits (default 1 req/sec).
Recovery:
- If user doesn't have target queries, derive from
<title>tags of top nav + top 10 referrer pages. - If full crawl is impossible (auth-walled site), audit the public surface + provide a sitemap-based audit for internal pages.
============================================================ === PHASE 1: CRAWL & INDEX AUDIT ===
Most ranking issues in 2026 trace back to crawl/index — audit before optimizing content.
Check:
- robots.txt parity — fetch as Googlebot, GPTBot, PerplexityBot, ClaudeBot. Identical access? Flag any bot-specific blocks.
- Sitemap correctness — fetch
/sitemap.xml. Verify each listed URL returns 200, has lastmod, isn't noindex. - Canonical chain — for each page, follow
rel=canonical. Catch self-canonical errors, redirect chains, conflicting hreflang. - Indexability —
<meta name="robots">,X-Robots-Tagheaders. Spot pages set to noindex unintentionally. - HTTP status distribution — count 200/301/302/404/410/500. Excessive 302→301 chains hurt; soft-404s (200 status with empty content) are the silent killer.
- Pagination & faceted nav — are search/filter URLs canonicalized to parent OR noindexed?
Generate seo/crawl_report.md with the index status of every important URL.
VALIDATION: Every URL in the report has a definitive status (Indexable / Blocked / Redirected / Error). No "unknown" rows.
FALLBACK: If crawl is rate-limited mid-run, persist partial results and resume later.
============================================================ === PHASE 2: AI CRAWLER PARITY ===
(See geo-optimize Phase 1 for full detail.)
Run the user-agent matrix test. Diff rendered (Playwright) vs static (curl as GPTBot, PerplexityBot, OAI-SearchBot, ClaudeBot, Claude-Web, Google-Extended, Applebot-Extended).
P0 if any AI bot sees < 50% of the rendered text or schema is missing in static HTML.
VALIDATION: Parity report contains a row per page × per bot with content diff %.
============================================================ === PHASE 3: CORE WEB VITALS (2026 THRESHOLDS) ===
Run Lighthouse CI for each priority URL on both mobile and desktop. Capture:
- LCP (Largest Contentful Paint): < 2.5s (good), 2.5–4.0s (needs improvement), > 4.0s (poor)
- INP (Interaction to Next Paint): < 200ms (good), 200–500ms (needs improvement), > 500ms (poor) — REPLACED FID in March 2024
- CLS (Cumulative Layout Shift): < 0.1 (good), 0.1–0.25 (needs improvement), > 0.25 (poor)
- TTFB (Time to First Byte): < 0.8s (good)
- Total Blocking Time (lab proxy for INP)
For each fail, generate a specific fix:
- LCP fail: preload hero image, eliminate render-blocking CSS/JS, use modern image formats (AVIF/WebP), CDN for hero.
- INP fail: split long tasks, defer non-critical JS, debounce input handlers, use
requestIdleCallback. - CLS fail: explicit width/height on images, reserve space for ads, avoid font-swap layout jump (use
font-display: optionalorsize-adjust).
VALIDATION: Each fail has a concrete code-level fix, not "improve performance."
============================================================ === PHASE 4: ON-PAGE AUDIT ===
Per priority URL, check:
- Title tag: 30–60 chars, unique site-wide, includes target query naturally (not stuffed), brand at end.
- Meta description: 120–160 chars, action-oriented, includes primary entity. Note: AI Overviews often pull from H1+first paragraph, not meta — but meta still drives SERP CTR for classic search.
- H1: exactly one per page, contains primary entity.
- Heading hierarchy: H1 → H2 → H3 (no skipping levels). Each H2 is a question or noun phrase that maps to a search intent.
- Image alt text: every content image has descriptive alt (not "image1.jpg" or empty).
- Internal linking: each priority page has ≥ 3 inbound internal links from contextually related pages. Anchor text varied (not all "click here").
- Outbound citations: at least 2 outbound links to authoritative third-party sources (E-E-A-T signal — AI engines mirror your citation behavior).
- First paragraph: states the answer to the page's primary query in plain language within the first 80 words. AI engines extract this as the citation snippet.
Generate seo/onpage_report.md per-URL.
VALIDATION: Report flags specific elements, not just "needs work."
============================================================ === PHASE 5: SCHEMA & ENTITY AUDIT ===
(Delegated to geo-optimize Phases 3 + 4.)
For each priority page, audit JSON-LD coverage and entity density. Generate missing schema. Recommend entity additions to hit ≥ 15 recognized entities per pillar page.
VALIDATION: Per-page entity count and schema validation status.
============================================================ === PHASE 6: CONTENT QUALITY & E-E-A-T ===
Per priority page:
- Author byline present and linked to
/author/{slug}? - Author Person page exists with bio +
sameAsto LinkedIn / Wikidata / X / Crunchbase? - Last-updated date visible in DOM and in Article schema
dateModified? - Original content markers — original screenshots / data / interviews / first-hand experience? (Not just rewritten generic content.)
- Citations within body to primary sources?
- HTTPS, no mixed content, valid SSL cert?
- About / Contact / Privacy pages present and linked from footer? (Trust signal.)
Generate seo/eeat_report.md with per-page and per-author scores.
VALIDATION: Each author has either a complete Person profile (5+ checkboxes pass) or a clear remediation list.
============================================================ === PHASE 7: COMPETITIVE GAP ===
For each priority query:
- SERP scrape top 10 organic + top 5 AI Overview citations (note: those overlap ~70%).
- Extract competitor entities, headings, schema types, word count.
- Diff vs the user's page: entities they cite that you don't, headings they cover that you don't, schema types they have that you don't.
- Output as a per-query gap matrix.
VALIDATION: Per-query gap report identifies at least 3 concrete additions (entities or sections) to add.
FALLBACK: If SERP scraping is rate-limited, fall back to manual top-3 analysis via the user's browser (instruct them, don't claim full coverage).
============================================================ === PHASE 8: PRIORITIZED PUNCH LIST ===
Single output seo/audit_report.md ranking findings:
# SEO Audit — {site} — {date}
## Executive Summary
- Indexability: {green/yellow/red} ({N} pages indexable / {M} blocked)
- AI Crawler Parity: {green/yellow/red} ({N} priority pages pass)
- Core Web Vitals: {N/M priority pages passing all 3}
- Schema Coverage: {N%} of priority pages have complete schema
- Entity Density: {N/M priority pages ≥15 entities}
- E-E-A-T: {N/M pages have linked author Person entity}
## P0 — Blocking Issues
- [ ] Site renders client-side, GPTBot sees empty HTML. Move /blog/\* to SSR via Next.js getServerSideProps OR pre-render via next-build.
- [ ] Missing Organization schema on homepage. (Generate JSON-LD — see fix snippet below.)
## P1 — High-Impact Fixes
- [ ] 6 of 10 priority pages fail INP > 500ms. Defer analytics.js and reduce main-thread blocking in checkout.js.
- [ ] 4 of 10 priority pages have < 15 entities. Add brand + product entity mentions per page (specifics in entity_audit.md).
## P2 — Medium-Impact
- [ ] No llms.txt at root.
- [ ] FAQPage schema missing on 3 pages with FAQ sections.
## P3 — Polish
- [ ] 14 images missing alt text in /blog/\*.
## Re-audit Checklist
After fixes, re-run with `/seo-audit-2026 {site}` and verify P0/P1 items move to ✅.
VALIDATION: Punch list ranked by impact, capped at top 20 items. Each P0/P1 includes a code-level fix or precise file path.
============================================================ === SELF-REVIEW ===
Score 1–5:
- Complete: All 8 phases ran? AI crawler parity tested? CWV measured on both mobile + desktop?
- Robust: Handled CSR sites, paywalled sites, rate limits, missing tools?
- Clean: Punch list is prioritized, not a 200-item dump?
- 2026-current: References INP (not FID), AI Overview citations, llms.txt, entity density, E-E-A-T binary gating? Doesn't recommend obsolete tactics (keyword density tuning, exact-match anchors at scale, doorway pages)?
Most common gap: failing to test AI crawler parity AND not measuring INP. These are the two table-stakes items that catch teams still running 2023-era audits.
============================================================ === LEARNINGS CAPTURE ===
Append to ~/.claude/skills/seo-audit-2026/LEARNINGS.md:
— <site, vertical, framework>
- What worked:
- What was awkward: <retry/manual fix needed>
- Suggested patch:
- Verdict: [Smooth / Minor friction / Major friction]
============================================================ === STRICT RULES ===
- Never use FID. It was retired March 2024. Use INP.
- Never recommend keyword density tuning. Entity density and topical authority are the modern signals.
- Never dump a 200-item checklist. Prioritize.
- Never claim "SEO complete" without AI crawler parity + schema validation + entity audit.
- Never overlook E-E-A-T author entity. 96% of AI citations come from strong-EEAT sources — it's a gate, not a polish.
- If the user only wants the AI search portion, route to
/geo-optimizeinstead of running the full classic audit.