Complete Technical SEO Audit Checklist for 2025

A technical SEO audit reveals the issues preventing your site from ranking—and gives you a prioritized roadmap to fix them. This checklist covers everything you need to evaluate, from Core Web Vitals to JavaScript rendering.

Use this as your audit framework, checking each item and noting issues for your fix list.

Core Web Vitals & Page Experience

Google uses page experience as a ranking factor. These metrics matter.

Largest Contentful Paint (LCP)

Target: Under 2.5 seconds

What to check:

• Measure LCP for key landing pages in PageSpeed Insights
• Identify the LCP element on each page (usually hero image or H1)
• Check image optimization (WebP, proper sizing, lazy loading)
• Evaluate server response time (TTFB)
• Review render-blocking resources (CSS, JavaScript)
• Check for excessive third-party scripts

Common fixes:

• Optimize and lazy-load images below the fold
• Preload critical resources
• Use CDN for static assets
• Minimize render-blocking CSS/JS
• Implement server-side rendering for critical content

Cumulative Layout Shift (CLS)

Target: Under 0.1

What to check:

• Run Lighthouse audit and note CLS-causing elements
• Check for images/embeds without dimensions
• Evaluate dynamic content insertion (ads, banners)
• Review font loading behavior (FOUT/FOIT)
• Check for late-loading above-fold content

Common fixes:

• Set explicit width/height on images and videos
• Reserve space for ads and dynamic content
• Use font-display: swap with size-matched fallbacks
• Avoid inserting content above existing content

Interaction to Next Paint (INP)

Target: Under 200 milliseconds

What to check:

• Test interactive elements (buttons, forms, navigation)
• Measure JavaScript execution time
• Check for long tasks blocking the main thread
• Evaluate third-party script impact

Common fixes:

• Break up long JavaScript tasks
• Defer non-critical JavaScript
• Use web workers for heavy computation
• Optimize event handlers

Crawlability

If Google can’t crawl your pages, they can’t rank.

Robots.txt

• Verify robots.txt is accessible at /robots.txt
• Check for unintentional blocks (blocking CSS/JS, key directories)
• Ensure sitemap is referenced
• Verify Googlebot-specific rules aren’t overly restrictive
• Test with Google’s robots.txt tester

XML Sitemaps

• Sitemap exists and is referenced in robots.txt
• Sitemap is under 50MB and 50,000 URLs per file
• Only indexable, canonical URLs are included
• Lastmod dates are accurate
• Sitemap is submitted in Google Search Console
• Compare sitemap URLs to indexed URLs

Internal Linking

• Key pages are within 3 clicks from homepage
• No orphan pages (pages with no internal links)
• Anchor text is descriptive and varied
• Navigation is crawlable (not JavaScript-only)
• Check for broken internal links

Crawl Budget (for large sites)

• Review crawl stats in Search Console
• Identify pages with excessive parameters
• Check for infinite crawl traps (calendars, filters)
• Ensure low-value pages are noindexed or blocked

Indexing

Crawled pages should be indexed—unless you don’t want them to be.

Index Coverage

• Review Index Coverage report in Search Console
• Investigate “Excluded” pages—are exclusions intentional?
• Check for “Discovered - currently not indexed” issues
• Verify important pages are in “Valid” category
• Test indexability of key pages with URL Inspection

Canonical Tags

• Every page has a self-referencing canonical
• Canonicals point to the correct preferred version
• No conflicting canonical signals (canonical vs. redirect)
• Canonicals use absolute URLs
• Paginated pages have appropriate canonicals

Noindex Tags

• Intentionally noindexed pages are actually noindexed
• No accidental noindex on important pages
• Check for noindex in HTTP headers (not just meta tags)
• Verify robots meta tags are not conflicting

Duplicate Content

• Run a crawl to identify duplicate title tags
• Check for URL parameter variations creating duplicates
• Verify www vs. non-www redirects
• Check HTTP vs. HTTPS consolidation
• Identify near-duplicate content across pages

URL Structure

Clean URLs help users and search engines.

URL Best Practices

• URLs are descriptive and readable
• URLs use hyphens, not underscores
• No excessive parameters or session IDs
• Consistent trailing slash usage
• Lowercase URLs (no case sensitivity issues)
• Reasonable URL length (under 100 characters)

Redirects

• 301 redirects for permanently moved content
• No redirect chains (more than 1 hop)
• No redirect loops
• HTTPS redirects properly implemented
• Old URLs redirect to relevant new content (not all to homepage)

Structured Data

Schema markup enables rich results and helps Google understand your content.

Implementation

• Test pages with Rich Results Test
• No errors in structured data
• Warnings are reviewed and addressed where possible
• Schema is on all appropriate page types

Common Schema Types

• Organization/Person schema on homepage/about
• Article/BlogPosting on blog posts
• Product schema on product pages
• FAQ schema on relevant pages
• Service schema on service pages
• BreadcrumbList for navigation
• LocalBusiness for local SEO

Mobile Usability

Mobile-first indexing means mobile matters most.

Mobile-Friendly Test

• Pass Google’s Mobile-Friendly Test
• No horizontal scrolling required
• Tap targets are appropriately sized
• Font sizes are readable without zooming
• No intrusive interstitials

Responsive Design

• Same content available on mobile and desktop
• Images scale appropriately
• Navigation is usable on touch devices
• No content hidden from mobile by default

Security

HTTPS is a ranking factor and a trust signal.

HTTPS Implementation

• Entire site served over HTTPS
• Valid SSL certificate (not expired)
• No mixed content warnings
• HTTP to HTTPS redirects in place
• HSTS header implemented

JavaScript SEO

For JavaScript-heavy sites, rendering is critical.

Rendering

• Test rendering with URL Inspection tool
• Critical content visible in rendered HTML
• Compare source HTML to rendered HTML
• Check that important links are in initial HTML (or rendered quickly)

JavaScript Issues

• No JavaScript errors blocking content
• Critical content doesn’t require JavaScript
• Lazy-loaded content is crawlable
• Infinite scroll uses proper implementation

International SEO (if applicable)

For sites targeting multiple regions/languages.

Hreflang

• Hreflang tags on all language/region variants
• Return links between all variants
• x-default specified
• No hreflang errors in Search Console
• Language/region codes are correct

Site Architecture

Good architecture helps users and search engines navigate.

Information Architecture

• Clear content hierarchy
• Logical category structure
• Flat site architecture (few clicks to deep pages)
• Consistent navigation across site

Pagination

• Paginated series use rel=“prev/next” or single-page approach
• Page 1 is canonical for the series
• Users can navigate between pages
• Infinite scroll properly implemented if used

After the Audit

Once you’ve completed the checklist:

1. Prioritize issues by impact and effort
2. Create fix tickets with specific actions
3. Set baselines for metrics you’ll improve
4. Implement fixes in priority order
5. Re-test after implementation
6. Monitor rankings and traffic for improvements

Technical SEO is never “done”—it’s ongoing maintenance as your site evolves.