Technical SEO forms the foundation of organic search success. Even the best content won't rank if search engines can't properly crawl, index, and understand your site. This comprehensive checklist covers every critical technical element you need to audit.
Why Technical SEO Audits Matter
73% of websites have technical issues negatively impacting SEO performance. Regular audits identify problems before they cause ranking drops or traffic loss.
Common Impact of Technical Issues
- Crawl errors: Pages invisible to Google
- Slow page speed: 53% of mobile users abandon sites loading over 3 seconds
- Mobile issues: 63% of organic traffic now mobile
- Indexation problems: Content not appearing in search results
- Structural issues: Poor internal linking architecture
1. Crawlability & Indexation
Robots.txt Audit
Check These Elements:
- ✅ Robots.txt accessible at domain.com/robots.txt
- ✅ Not blocking critical pages or resources (CSS, JS, images)
- ✅ XML sitemap referenced in robots.txt
- ✅ User-agent directives correctly configured
- ✅ No accidental "Disallow: /" blocking entire site
Test Command:
curl https://yoursite.com/robots.txt
XML Sitemap Verification
Essential Sitemap Checks:
- ✅ Sitemap exists and accessible at /sitemap.xml
- ✅ All important pages included
- ✅ No 404, 301, or 302 URLs in sitemap
- ✅ Less than 50,000 URLs per sitemap
- ✅ Submitted to Google Search Console
- ✅ Lastmod dates accurate
- ✅ Image and video sitemaps if applicable
Test Your Sitemap:
- Validate at xml-sitemaps.com
- Check Google Search Console coverage report
- Verify mobile sitemap if separate
Indexation Status
Google Search Console Checks:
- Total indexed pages vs. submitted pages
- Coverage errors and warnings
- Excluded pages (reasons for exclusion)
- Discover performance (if eligible)
- Mobile usability issues
Manual Checks:
site:yoursite.com
site:yoursite.com/blog/
site:yoursite.com inurl:product
Canonical Tags
Audit Requirements:
- ✅ Every page has self-referencing canonical tag
- ✅ Canonical points to correct version (www vs non-www, https)
- ✅ No canonicals pointing to 404s or redirects
- ✅ Paginated pages handled correctly
- ✅ Parameter URLs canonicalized appropriately
2. Site Architecture & Internal Linking
URL Structure
Best Practices Checklist:
- ✅ URLs are descriptive and keyword-rich
- ✅ Consistent URL structure across site
- ✅ Lowercase letters only
- ✅ Hyphens separating words (not underscores)
- ✅ No unnecessary parameters
- ✅ Logical hierarchy (site.com/category/subcategory/page)
- ✅ URLs under 115 characters ideally
Bad URL Examples:
❌ site.com/product.php?id=12345&category=23
❌ site.com/THIS-HAS-CAPS
❌ site.com/keyword_with_underscores
Good URL Examples:
✅ site.com/products/blue-widgets
✅ site.com/blog/seo-tips
✅ site.com/services/local-seo
Internal Linking Audit
Critical Factors:
- ✅ All pages accessible within 3 clicks from homepage
- ✅ Orphan pages identified and linked
- ✅ Descriptive anchor text (not "click here")
- ✅ Important pages have more internal links
- ✅ Broken internal links fixed
- ✅ Relevant contextual links between related content
Tools to Use:
- Screaming Frog (crawl depth analysis)
- Ahrefs Site Audit (internal link opportunities)
- Google Analytics (navigation paths)
Navigation & Hierarchy
Evaluation Criteria:
- ✅ Clear, logical navigation structure
- ✅ Breadcrumb navigation implemented
- ✅ HTML sitemap for users
- ✅ Footer links to important pages
- ✅ No excessive dropdown layers (max 3 levels)
- ✅ Search functionality for large sites
3. Page Speed & Core Web Vitals
Core Web Vitals Targets
LCP (Largest Contentful Paint): Under 2.5 seconds
- Measures loading performance
- Optimize images and server response time
- Use CDN for faster delivery
FID (First Input Delay): Under 100 milliseconds
- Measures interactivity
- Minimize JavaScript execution
- Break up long tasks
CLS (Cumulative Layout Shift): Under 0.1
- Measures visual stability
- Set size attributes for images/videos
- Avoid inserting content above existing content
- Use transform animations instead of properties triggering layout
PageSpeed Optimization
Critical Optimizations:
- ✅ Enable compression (Gzip or Brotli)
- ✅ Minify CSS, JavaScript, HTML
- ✅ Leverage browser caching
- ✅ Optimize images (WebP format, proper sizing)
- ✅ Eliminate render-blocking resources
- ✅ Use lazy loading for images below fold
- ✅ Implement CDN (Cloudflare, Fastly)
- ✅ Reduce server response time (TTFB under 600ms)
Testing Tools:
- Google PageSpeed Insights
- GTmetrix
- WebPageTest
- Chrome DevTools Lighthouse
Mobile Performance
Mobile-Specific Checks:
- ✅ Passes Google Mobile-Friendly Test
- ✅ No intrusive interstitials
- ✅ Touch elements properly sized (48x48px minimum)
- ✅ Viewport configured correctly
- ✅ Font sizes readable (minimum 16px)
- ✅ Mobile page speed under 3 seconds
4. On-Page Technical Elements
Title Tags
Audit Criteria:
- ✅ Unique title on every page
- ✅ Primary keyword included
- ✅ 50-60 characters (avoid truncation)
- ✅ Brand name included (end of title)
- ✅ Compelling and click-worthy
- ✅ No duplicate titles across site
Meta Descriptions
Checklist:
- ✅ Unique description per page
- ✅ 150-160 characters
- ✅ Includes target keyword naturally
- ✅ Contains call-to-action
- ✅ Accurately describes page content
- ✅ Missing descriptions identified
Header Tags (H1-H6)
Structure Requirements:
- ✅ One H1 per page
- ✅ H1 contains primary keyword
- ✅ Logical hierarchy (H1 > H2 > H3)
- ✅ Not skipping levels (H2 to H4)
- ✅ Headers describe section content
- ✅ Not used solely for styling
Image Optimization
Technical Image Audit:
- ✅ All images have descriptive alt text
- ✅ File names descriptive (blue-widget.svg not IMG_1234.svg)
- ✅ Appropriate file formats (WebP, JPEG, PNG)
- ✅ Images properly compressed
- ✅ Responsive images for different screen sizes
- ✅ Lazy loading implemented
- ✅ Image sitemaps for image-heavy sites
5. Structured Data & Schema Markup
Schema Implementation
Priority Schema Types:
- ✅ Organization schema on homepage
- ✅ LocalBusiness schema (for local businesses)
- ✅ Product schema (for e-commerce)
- ✅ Article schema (for blog content)
- ✅ FAQ schema (for FAQ pages)
- ✅ Review/Rating schema (where applicable)
- ✅ Breadcrumb schema on all pages
- ✅ VideoObject schema (for video content)
Validation Tools:
- Google Rich Results Test
- Schema.org Validator
- Structured Data Testing Tool
Implementation Methods:
- JSON-LD (Google's recommended format)
- Microdata
- RDFa
Common Schema Errors
Avoid These Mistakes:
- Missing required properties
- Invalid property values
- Marking up invisible content
- Incorrect nesting of schema types
- Outdated schema versions
- Review schema violations (Google guidelines)
6. HTTPS & Security
SSL/TLS Audit
Security Checklist:
- ✅ Valid SSL certificate installed
- ✅ All pages load over HTTPS
- ✅ HTTP redirects to HTTPS (301)
- ✅ Mixed content warnings resolved
- ✅ Internal links use HTTPS
- ✅ Canonical tags use HTTPS
- ✅ Hreflang tags use HTTPS (if applicable)
Test Security:
https://www.ssllabs.com/ssltest/
Security Headers
Recommended Headers:
Strict-Transport-Security: max-age=31536000
Content-Security-Policy: default-src 'self'
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
7. International SEO (If Applicable)
Hreflang Implementation
Audit Steps:
- ✅ Hreflang tags on all international pages
- ✅ Correct language/region codes (en-us, en-gb, es-mx)
- ✅ Self-referencing hreflang
- ✅ Return links present (bidirectional)
- ✅ X-default specified for default version
- ✅ Consistent URLs across hreflang tags
Example Implementation:
<link rel="alternate" hreflang="en-us" href="https://example.com/en-us/" />
<link rel="alternate" hreflang="en-gb" href="https://example.com/en-gb/" />
<link rel="alternate" hreflang="x-default" href="https://example.com/" />
International Structure
Options to Consider:
- ccTLDs (example.co.uk, example.de)
- Subdirectories (example.com/uk/, example.com/de/)
- Subdomains (uk.example.com, de.example.com)
8. JavaScript SEO
JavaScript Rendering
Critical Checks:
- ✅ Important content not hidden in JavaScript
- ✅ Google can render JavaScript (test in Search Console)
- ✅ No infinite scroll issues for crawling
- ✅ Internal links crawlable (not JS-only)
- ✅ Meta tags accessible to crawlers
- ✅ Lazy loading doesn't block critical content
Testing:
- View page source vs. rendered HTML
- Chrome DevTools Network tab (disable JavaScript)
- Google Search Console URL Inspection Tool
Client-Side Rendering Issues
Common Problems:
- Content not visible in initial HTML
- Links not crawlable
- Metadata missing from source
- Slow rendering blocking indexation
9. Redirects & Status Codes
Redirect Audit
Verify:
- ✅ 301 redirects for permanent moves
- ✅ 302 redirects only for temporary changes
- ✅ No redirect chains (A→B→C)
- ✅ No redirect loops
- ✅ Redirect to relevant pages (not homepage)
- ✅ HTTPS redirects in place
Find Redirect Issues:
# Using curl
curl -I https://yoursite.com/old-page
# Check for chains
curl -L -I https://yoursite.com/old-page
404 Error Management
404 Best Practices:
- ✅ Custom 404 page with helpful navigation
- ✅ Search functionality on 404 page
- ✅ Suggestions for similar content
- ✅ Monitor 404s in Google Search Console
- ✅ Fix broken internal links causing 404s
- ✅ 301 redirect valuable 404 pages with backlinks
10. Log File Analysis
Server Log Insights
What to Analyze:
- Crawl frequency and patterns
- Crawled vs. not crawled pages
- Crawl budget waste
- Bot activity (Googlebot, Bingbot)
- Server errors (5xx responses)
- Slow-loading pages for bots
Tools:
- Screaming Frog Log File Analyzer
- Splunk
- ELK Stack (Elasticsearch, Logstash, Kibana)
Technical SEO Tools
Essential Tools
Free Tools:
- Google Search Console
- Google PageSpeed Insights
- Google Mobile-Friendly Test
- Google Rich Results Test
- Bing Webmaster Tools
Paid Tools:
- Screaming Frog SEO Spider ($259/year)
- Ahrefs Site Audit ($99+/month)
- SEMrush Site Audit ($119+/month)
- Sitebulb ($35+/month)
- DeepCrawl ($540+/month)
Monthly Technical SEO Checklist
Routine Maintenance:
- ✅ Review Google Search Console coverage errors
- ✅ Check Core Web Vitals report
- ✅ Monitor crawl stats and resources
- ✅ Audit new 404 errors
- ✅ Review site speed metrics
- ✅ Check for manual actions or security issues
- ✅ Validate structured data
- ✅ Monitor server uptime
- ✅ Check for broken links
- ✅ Review mobile usability issues
Conclusion
Technical SEO isn't a one-time task—it requires ongoing monitoring and optimization. Regular audits catch issues before they impact rankings and ensure your site meets Google's evolving technical standards.
Start with the critical issues (crawlability, indexation, site speed) and work through the comprehensive checklist systematically. Most sites can address 80% of technical issues within 30-60 days.
Remember: technical SEO enables your content to perform. Without a solid technical foundation, even the best content strategy will underperform.
Need expert help with technical SEO? Our specialists conduct comprehensive technical audits and implement fixes that improve crawlability, speed, and rankings. Schedule a technical SEO audit today.