Technical SEO Audit

You need to assess a website's technical SEO health. Produces a comprehensive checklist covering crawlability, site speed (Core Web Vitals), schema markup, mobile-friendliness, indexation, redirect chains, and security. Works for initial audits, pre-launch reviews, or diagnosing organic traffic drops.

How it works

1. You provide the site URL and any known issues or symptoms (e.g., traffic drop, pages not indexing)
2. The skill walks through each technical SEO category with specific checks, flags issues, and prioritizes fixes by impact
3. Use the output as a remediation roadmap for developers or hand it to a technical SEO specialist for validation

Related skills: Feeds keyword context from /seo-keyword-discovery. Informs content optimization via /content-seo-brief.

Prompt

You are conducting a technical SEO audit. Your job is to produce a structured, prioritized checklist that a developer or site owner can act on. Be specific about what to check, what "good" looks like, and what the fix is when something is wrong.

Inputs I will provide:

• Site URL: {{SITE_URL}} (e.g., "https://example.com")
• Known issues (optional): {{KNOWN_ISSUES}} (e.g., "Pages dropped from index last month" or "Core Web Vitals failing on mobile")
• CMS/platform (optional): {{PLATFORM}} (e.g., "WordPress with Yoast" or "Next.js on Vercel." Helps tailor recommendations.)
• Priority pages (optional): {{PRIORITY_PAGES}} (e.g., "Homepage, /pricing, /blog/* -- these drive 80% of traffic")

Step 1: Crawlability and indexation

Check whether search engines can discover, crawl, and index the site's important pages.

### Crawlability and Indexation

**robots.txt**
- [ ] robots.txt exists and is accessible at {{SITE_URL}}/robots.txt
- [ ] No critical pages or directories are accidentally blocked
- [ ] Sitemap URL is declared in robots.txt
- [ ] Crawl-delay directive reviewed (if present)
- Finding: {{what was found}}
- Issue: {{specific problem, or "No issues"}}
- Fix: {{specific remediation}}

**XML Sitemap**
- [ ] Sitemap exists and is accessible (typically /sitemap.xml or /sitemap_index.xml)
- [ ] Sitemap is submitted to Google Search Console
- [ ] All important pages are included
- [ ] No 404, 301, or noindex pages in the sitemap
- [ ] Sitemap is under 50MB / 50,000 URLs per file
- [ ] Last modified dates are accurate (not all the same date)
- Finding: {{what was found}}
- Issue: {{specific problem, or "No issues"}}
- Fix: {{specific remediation}}

**Indexation Status**
- [ ] site: search shows expected number of indexed pages
- [ ] No unexpected pages indexed (staging, test, duplicate)
- [ ] No important pages missing from index
- [ ] Canonical tags are present and self-referencing (or pointing correctly)
- [ ] No conflicting noindex directives (meta tag vs. header vs. robots.txt)
- [ ] Pagination handled correctly (rel=next/prev or load-more patterns)
- Indexed pages: {{count or "check via Search Console"}}
- Issue: {{specific problem, or "No issues"}}
- Fix: {{specific remediation}}

**Crawl Budget (for larger sites, 10,000+ pages)**
- [ ] Faceted navigation not generating infinite crawl paths
- [ ] URL parameters handled (Search Console parameter tool or canonical tags)
- [ ] Internal search result pages blocked from crawling
- [ ] Thin or duplicate content not consuming crawl budget
- Issue: {{specific problem, or "Not applicable for site size"}}

Step 2: Site speed and Core Web Vitals

Assess loading performance using the three Core Web Vitals metrics plus supplementary speed indicators.

### Site Speed and Core Web Vitals

**Largest Contentful Paint (LCP) -- target: under 2.5 seconds**
- [ ] Measure LCP on mobile and desktop (PageSpeed Insights or CrUX data)
- [ ] Identify the LCP element (hero image, heading text, video)
- [ ] Check image optimization: format (WebP/AVIF), compression, sizing
- [ ] Check server response time (TTFB under 800ms)
- [ ] Check render-blocking resources (CSS, JS in critical path)
- Mobile LCP: {{value or "measure needed"}}
- Desktop LCP: {{value or "measure needed"}}
- Issue: {{specific bottleneck, or "Passing"}}
- Fix: {{specific remediation with expected impact}}

**First Input Delay (FID) / Interaction to Next Paint (INP) -- target: under 200ms**
- [ ] Measure INP (replaced FID as Core Web Vital in March 2024)
- [ ] Identify heavy JavaScript execution blocking main thread
- [ ] Check third-party script impact (analytics, chat widgets, ads)
- [ ] Review event handler responsiveness
- INP: {{value or "measure needed"}}
- Issue: {{specific bottleneck, or "Passing"}}
- Fix: {{specific remediation}}

**Cumulative Layout Shift (CLS) -- target: under 0.1**
- [ ] Measure CLS on key page templates
- [ ] Check for images/videos without explicit dimensions
- [ ] Check for dynamically injected content (ads, banners, cookie notices)
- [ ] Check for web fonts causing layout shift (font-display strategy)
- CLS: {{value or "measure needed"}}
- Issue: {{specific cause, or "Passing"}}
- Fix: {{specific remediation}}

**Supplementary Speed Checks**
- [ ] Total page weight: {{size}} (target: under 3MB for most pages)
- [ ] Number of HTTP requests: {{count}} (target: minimize)
- [ ] Browser caching headers configured (Cache-Control, ETag)
- [ ] Gzip/Brotli compression enabled
- [ ] CDN in use for static assets
- [ ] Critical CSS inlined, non-critical CSS deferred

Step 3: Schema markup review

Evaluate structured data implementation for search result enrichment.

### Schema Markup (JSON-LD)

**Implementation Check**
- [ ] Schema markup present on key page types
- [ ] Using JSON-LD format (preferred by Google)
- [ ] Validates without errors in Google Rich Results Test
- [ ] Validates without errors in Schema.org validator

**Page-Type Coverage**
| Page Type | Recommended Schema | Implemented? | Valid? | Notes |
|-----------|-------------------|-------------|--------|-------|
| Homepage | Organization, WebSite | {{yes/no}} | {{yes/no/errors}} | {{notes}} |
| Blog posts | Article, BlogPosting | {{yes/no}} | {{yes/no/errors}} | {{notes}} |
| Product pages | Product, Offer | {{yes/no}} | {{yes/no/errors}} | {{notes}} |
| Service pages | Service, LocalBusiness | {{yes/no}} | {{yes/no/errors}} | {{notes}} |
| FAQ pages | FAQPage | {{yes/no}} | {{yes/no/errors}} | {{notes}} |
| Contact page | LocalBusiness, ContactPoint | {{yes/no}} | {{yes/no/errors}} | {{notes}} |

**Missing Opportunities**
- {{schema type that could be added for SERP enrichment}}
- {{schema type that competitors use but this site does not}}

**Common Errors Found**
- {{error description, or "No errors"}}
- Fix: {{specific remediation}}

Step 4: Mobile-friendliness

### Mobile-Friendliness

- [ ] Site uses responsive design (not separate mobile URLs or dynamic serving)
- [ ] Viewport meta tag configured correctly
- [ ] Text readable without zooming (16px+ base font)
- [ ] Tap targets adequately sized and spaced (48px+ with 8px+ spacing)
- [ ] No horizontal scrolling on mobile viewports
- [ ] Mobile navigation is accessible and functional
- [ ] Forms are usable on mobile (input types, autocomplete attributes)
- [ ] Pop-ups and interstitials comply with Google's guidelines (no intrusive interstitials)
- [ ] Mobile page speed passes Core Web Vitals (see Step 2)
- Issue: {{specific problem, or "No issues"}}
- Fix: {{specific remediation}}

Step 5: Redirect chain audit

### Redirects

**Redirect Chains**
- [ ] No redirect chains longer than 2 hops (ideal: 1 hop)
- [ ] Redirect chains identified and shortened to direct 301s
- Chain count: {{number found or "audit needed with Screaming Frog / Ahrefs"}}
- Worst chain: {{example chain, or "None"}}

**Redirect Audit**
- [ ] All redirects use 301 (permanent) unless temporarily moved
- [ ] No redirect loops detected
- [ ] Old URLs from site migrations still redirect correctly
- [ ] HTTP to HTTPS redirect in place (single hop)
- [ ] www to non-www (or vice versa) redirect in place (single hop)
- [ ] Trailing slash behavior is consistent

**Orphan Pages**
- [ ] All important pages are reachable through internal links (not just sitemap)
- [ ] No important pages require 4+ clicks from homepage
- Orphan pages found: {{count or "audit needed"}}

Step 6: Security

### Security (HTTPS and Mixed Content)

- [ ] Site loads on HTTPS by default
- [ ] Valid SSL/TLS certificate (not expired, correct domain)
- [ ] HTTP requests redirect to HTTPS (301, single hop)
- [ ] No mixed content warnings (HTTP resources loaded on HTTPS pages)
- [ ] HSTS header configured (Strict-Transport-Security)
- [ ] Security headers present: X-Content-Type-Options, X-Frame-Options, Content-Security-Policy
- Mixed content issues: {{count and examples, or "None"}}
- Certificate expiry: {{date}}
- Fix: {{specific remediation, or "No issues"}}

Step 7: Priority remediation plan

Rank all issues found by impact and effort.

### Priority Remediation Plan

| Priority | Issue | Category | Impact | Effort | Recommended Fix |
|----------|-------|----------|--------|--------|----------------|
| P0 (critical) | {{issue}} | {{category}} | {{high/medium/low}} | {{hours/days estimate}} | {{specific fix}} |
| P1 (high) | {{issue}} | {{category}} | {{impact}} | {{effort}} | {{fix}} |
| P2 (medium) | {{issue}} | {{category}} | {{impact}} | {{effort}} | {{fix}} |
| P3 (low) | {{issue}} | {{category}} | {{impact}} | {{effort}} | {{fix}} |

**Quick wins (high impact, low effort):**
1. {{fix}}
2. {{fix}}

**Monitoring plan:**
- Re-audit Core Web Vitals: {{frequency, e.g., monthly}}
- Check indexation status: {{frequency}}
- Review Search Console for new crawl errors: {{frequency}}