Technical SEO Audit: A Step-by-Step Checklist for 2025

A technical SEO audit is a systematic review of everything on your site that affects how search engines crawl, index, and rank your pages. Content and links matter, but neither helps much if Google can't properly access and understand your site.

This checklist covers the full scope. Work through it in order — the items near the top have more impact.

1. Crawlability

robots.txt

• Visit yourdomain.com/robots.txt — does it exist and load correctly?
• Is there an accidental Disallow: / blocking the whole site?
• Are CSS and JavaScript files blocked? (They shouldn't be)
• Is your sitemap declared? (Sitemap: https://yourdomain.com/sitemap.xml)

Sitemap

• Does your XML sitemap exist and load at /sitemap.xml?
• Is it submitted in Google Search Console?
• Does it include all important pages? Are 404 or non-canonical URLs excluded?
• Is it under 50,000 URLs and 50MB? If larger, split into a sitemap index.

Crawl Budget

For large sites (10,000+ pages), crawl budget matters. Signs of crawl budget problems: Search Console shows URLs discovered but not indexed, important pages take weeks to update after publishing, or the Index Coverage report shows many "Crawled, not currently indexed" entries.

• Block low-value URLs in robots.txt (search results, filter combinations, empty category pages)
• Use noindex on thin or duplicate pages
• Check internal link structure — pages with no internal links get crawled infrequently

2. Indexability

• Search site:yourdomain.com in Google — roughly how many pages are indexed? Does the number make sense?
• Check for <meta name="robots" content="noindex"> on pages that should be indexed
• Check for X-Robots-Tag: noindex in HTTP headers
• Verify the correct canonical URLs are set — are any important pages accidentally canonicalized to different URLs?
• Check the Index Coverage report in Google Search Console for errors, warnings, and excluded pages

3. HTTPS and Security

• Is the entire site on HTTPS with a valid, non-expired certificate?
• Does HTTP redirect to HTTPS via 301?
• Are there mixed content warnings (HTTP resources on HTTPS pages)?
• Check your SSL certificate expiry with our SSL Checker
• Is HSTS configured? (Strict-Transport-Security header present)

4. URL Structure

• Are URLs short, descriptive, and using hyphens (not underscores)?
• Is there URL consistency? (Trailing slash or not — pick one and enforce it everywhere)
• Are there any redirect chains longer than 2 hops? Chains dilute PageRank and waste crawl budget.
• Are there redirect loops?
• Are there canonical tags on all important pages, pointing to the preferred URL?

5. Duplicate Content

Duplicate content doesn't cause penalties in the classic sense, but it wastes crawl budget and dilutes ranking signals across multiple URLs.

• www vs non-www — is one redirecting to the other?
• HTTP vs HTTPS — redirecting?
• Trailing slash consistency
• URL parameters creating duplicate pages (/page?sort=asc same content as /page)
• Pagination handled correctly (paginated pages shouldn't dilute the main page's authority)
• Near-duplicate content across similar product or service pages

6. Page Speed and Core Web Vitals

Check both lab data (Lighthouse) and field data (Google Search Console Core Web Vitals report). They often differ significantly.

• LCP under 2.5 seconds (mobile)
• INP under 200ms
• CLS under 0.1
• TTFB under 600ms
• Check with our Website Speed Test and your Search Console Core Web Vitals report

7. Mobile

• Is the site responsive on mobile? Google uses mobile-first indexing for all sites now.
• No horizontal scrolling on mobile viewport
• Tap targets (buttons, links) are at least 48x48px — anything smaller fails accessibility and usability
• Font size 16px+ for body text on mobile (anything smaller forces users to zoom)
• Use Google's Mobile-Friendly Test to check any page

8. Internal Linking

• Check for orphan pages — pages with no internal links pointing to them
• Are your most important pages well-linked internally?
• Are internal links using descriptive anchor text (not "click here")?
• Check for broken internal links with Screaming Frog or similar

9. Structured Data

• Do important pages have relevant schema markup? (Article, FAQPage, Product, LocalBusiness, etc.)
• Is all schema valid? Check with Google's Rich Results Test.
• Are there schema errors or warnings in Search Console (Enhancements section)?

10. JavaScript Rendering

If your site uses heavy client-side JavaScript (React, Angular, Vue), Google needs to render it to see the content. Check by viewing source vs. rendered view in Screaming Frog, or use the URL Inspection tool in Search Console to see Google's rendered version.

• Is important content visible in the DOM before JavaScript runs? (Server-side rendering or static generation preferred)
• Are internal links in the HTML, not just generated by JavaScript?

11. International SEO (If Applicable)

• Is hreflang implemented correctly for multilingual sites?
• Do hreflang tags have return tags? (Every hreflang relationship must be bidirectional)
• Is there a clear URL structure for different regions/languages?

Recommended Tools for Technical Audits

• Screaming Frog SEO Spider — Free up to 500 URLs, essential for site crawls
• Google Search Console — Index coverage, CWV, manual actions, search performance
• Ahrefs or Semrush — Site audit features, backlink analysis
• Our SSL Checker, Speed Test, and HTTP Header Checker for specific technical checks

Run a technical audit on your entire site at least quarterly, and on any section you touch after major changes. Technical issues compound — one redirect chain leads to canonicalization confusion which leads to duplicate content signals. Catching them early is much easier than untangling a year of accumulated technical debt.