Your website could be losing 50% of potential traffic due to technical SEO issues you don't even know exist. This 25-point checklist helps you identify and fix critical problems systematically. For professional help, check our technical SEO services.
Part 1: Critical Technical Issues (10 Points)
1. Crawlability Problems
What to check: Can Google's bots access all important pages?
How to audit:
- Check robots.txt: yoursite.com/robots.txt
- Look for accidental "Disallow: /" blocking everything
- Verify important pages aren't blocked
Common mistakes:
- Blocking CSS/JavaScript files (hurts rendering)
- Blocking admin pages that link to product pages
- Wildcard disallows blocking entire sections
2. Indexation Status
What to check: Are your pages actually indexed by Google?
How to audit:
- Google Search Console → Coverage report
- Check "Valid" pages vs "Excluded"
- Site: operator search:
site:yoursite.com
Red flags:
- Important pages showing as "Excluded"
- Pages marked "Crawled - currently not indexed"
- Duplicate content issues
3. Site Speed & Core Web Vitals
What to check: Page load performance metrics
Tools:
- Google PageSpeed Insights
- GSC Core Web Vitals report
- Lighthouse (Chrome DevTools)
Target benchmarks:
- LCP (Largest Contentful Paint): <2.5s
- CLS (Cumulative Layout Shift): <0.1
- INP (Interaction to Next Paint): <200ms
For detailed optimization tactics, see our Core Web Vitals guide.
4. Mobile Usability
What to check: Mobile-friendliness and responsive design
How to audit:
- Google Mobile-Friendly Test
- GSC Mobile Usability report
- Test on real devices (iOS + Android)
Common issues:
- Text too small to read
- Clickable elements too close together
- Content wider than screen
- Viewport not set correctly
5. HTTPS & Security
What to check: SSL certificate status and mixed content
How to audit:
- Check for valid SSL: Look for padlock icon
- Scan for mixed content (HTTP resources on HTTPS pages)
- Verify www vs non-www redirect consistency
Critical: Google prioritizes HTTPS sites. No SSL = ranking penalty.
6. XML Sitemap Quality
What to check: Sitemap accuracy and submission
How to audit:
- Access sitemap: yoursite.com/sitemap.xml
- Verify all important pages included
- Check for 404/redirected URLs in sitemap
- Confirm submitted to GSC
Best practices:
- Update sitemap when adding/removing pages
- Include only indexable pages (no noindex pages)
- Use priority tags strategically
7. Page Load Time
What to check: Total page load speed
Target: Under 3 seconds for full page load
How to improve:
- Compress images (WebP format)
- Enable gzip/Brotli compression
- Minify CSS/JavaScript
- Use CDN for assets
- Implement browser caching
8. Server Response Time
What to check: Time to First Byte (TTFB)
Target: Under 200ms
How to check: Chrome DevTools → Network tab → Check timing
How to improve:
- Upgrade hosting (shared → VPS → dedicated)
- Use server-side caching (Redis, Memcached)
- Optimize database queries
- Use a CDN
9. Broken Links (404 Errors)
What to check: Internal and external broken links
How to audit:
- Screaming Frog SEO Spider (crawl site)
- GSC → Coverage → Not found (404)
- Ahrefs Site Audit
Priority: Fix internal 404s immediately. They waste crawl budget and hurt UX.
10. Redirect Chains
What to check: Multiple redirects in sequence
Bad example: Page A → Page B → Page C → Page D
Good example: Page A → Page D (direct)
Impact: Each redirect adds ~100-300ms delay. Google may not follow chains >3 hops.
Part 2: On-Page Technical SEO (8 Points)
11. Title Tag Optimization
Checklist:
- Unique title on every page
- 50-60 characters max
- Primary keyword near beginning
- Includes brand name
- Compelling & click-worthy
12. Meta Description Quality
Checklist:
- 150-160 characters
- Includes target keyword
- Clear call-to-action
- Accurately describes page content
13. Header Structure (H1-H6)
What to check: Proper heading hierarchy
Rules:
- One H1 per page (usually page title)
- H2s for main sections
- H3s for subsections under H2s
- Don't skip levels (H2 → H4)
- Include keywords naturally
14. Image Optimization
Checklist:
- Descriptive file names (not IMG_1234.jpg)
- Alt text on all images
- Compressed file sizes (<100KB ideal)
- WebP format where supported
- Width/height attributes to prevent CLS
- Lazy loading for below-fold images
15. Internal Linking Structure
What to check: Strategic links between pages
Best practices:
- Link to important pages from homepage
- Use descriptive anchor text (not "click here")
- Create topic clusters (pillar + cluster content)
- Fix orphan pages (pages with no internal links)
16. URL Structure
Good URL: /blog/technical-seo-audit-checklist
Bad URL: /page?id=12345&cat=blog&ref=home
Rules:
- Use hyphens (not underscores)
- Keep short and descriptive
- Include target keyword
- Use lowercase only
17. Canonical Tags
What to check: Duplicate content management
When to use:
- Product variants (color, size options)
- Pagination (all point to page 1)
- HTTP vs HTTPS versions
- www vs non-www versions
18. Schema Markup Implementation
What to check: Structured data presence and validity
Priority schema types:
- Organization
- LocalBusiness (if applicable)
- Article (blog posts)
- Product (e-commerce)
- FAQ
- Breadcrumb
Need help with schema? See our upcoming complete schema guide.
Part 3: Advanced Technical SEO (7 Points)
19. JavaScript Rendering
What to check: Can Google render your JavaScript content?
Test: URL Inspection tool in GSC → View "Rendered" vs "Raw HTML"
Issues to look for:
- Content only visible in rendered version (not ideal)
- Critical content missing from rendered version (very bad)
- Infinite scroll not loading content for bots
20. International SEO (Hreflang)
What to check: If you have multi-language/multi-region content
Hreflang attributes tell Google:
- Which language version to show users
- Which regional version to show (en-US vs en-GB)
Common mistakes:
- Missing return links (every page must reference all versions)
- Wrong language codes
- Self-referencing hreflang missing
21. Pagination Best Practices
Options for handling paginated content:
- Option 1: Canonical all to page 1 (simple, but page 2+ won't rank)
- Option 2: Let each page index separately (better for large archives)
- Option 3: Infinite scroll with pushState (complex but UX-friendly)
Best practice: Add "View All" page if feasible.
22. Duplicate Content Issues
Where to check:
- Screaming Frog → Content → Duplicates
- Copyscape for external duplication
- Siteliner for internal duplication
Common causes:
- www vs non-www
- HTTP vs HTTPS
- Trailing slash vs no trailing slash
- Product descriptions copied from manufacturer
- Boilerplate content on every page
23. Log File Analysis
What to check: What Google is actually crawling
Tools: Screaming Frog Log File Analyzer, Botify
Insights you get:
- Most crawled pages vs least crawled
- Crawl budget waste on unimportant pages
- Bot behavior patterns
- Server errors Google encountered
24. Core Web Vitals in Field Data
What to check: Real user performance data
Where to find: GSC → Experience → Core Web Vitals
Why field data matters: Lab data (Lighthouse) shows potential. Field data shows reality.
25. Security Headers
What to check: HTTP security headers presence
Test: securityheaders.com
Important headers:
- X-Content-Type-Options
- X-Frame-Options
- X-XSS-Protection
- Strict-Transport-Security
- Content-Security-Policy
Priority Matrix: What to Fix First
Critical (Fix Immediately):
- HTTPS implementation
- Mobile usability errors
- Broken internal links
- Indexation blocks (robots.txt, noindex)
- Core Web Vitals failures
High Priority (Fix This Week):
- Duplicate content issues
- Missing title tags / meta descriptions
- Schema markup implementation
- Image optimization
- Sitemap submission
Medium Priority (Fix This Month):
- Internal linking optimization
- Redirect chains
- Header structure cleanup
- URL structure improvements
- Security headers
Low Priority (Ongoing Optimization):
- Log file analysis
- Advanced JavaScript rendering
- International SEO (if not applicable)
Tools for Technical SEO Audits
Free Tools:
- Google Search Console (essential)
- Google PageSpeed Insights
- Google Mobile-Friendly Test
- Screaming Frog (free up to 500 URLs)
- Lighthouse (Chrome DevTools)
Paid Tools (Worth It):
- Ahrefs Site Audit ($99+/month)
- SEMrush Site Audit ($119+/month)
- Screaming Frog Pro ($259/year)
- Botify (enterprise, $500+/month)
Final Thoughts
A technical SEO audit isn't a one-time task. Run this checklist quarterly to catch issues before they impact rankings.
Pro tip: Schedule these audits:
- After major site updates
- After platform migrations
- Before and after Google algorithm updates
- Quarterly (minimum)
Need expert help? Our technical SEO audits include all 25 points plus custom recommendations for your industry.