A technical SEO audit reveals the infrastructure issues that prevent search engines from properly crawling, indexing, and ranking your site. You can have great content and strong backlinks, but if Google cannot access or understand your pages, rankings will suffer. A thorough audit checks everything from robots.txt configuration to canonical tag correctness to broken links.
This step-by-step guide walks through every component of a technical SEO audit using free tools. Budget 60 to 90 minutes for a thorough pass on a small-to-medium site.
Step 1: Crawl Your Site
Before fixing anything, understand how search engines see your site. A crawl reveals broken links, redirect chains, missing tags, and orphan pages that do not appear in your navigation.
- Start with the free SEO quick audit to get an instant health score for any URL.
- Check for 404 errors, 301 redirect chains, and 500 server errors.
- Look for pages with missing title tags, meta descriptions, or H1 tags.
Step 2: Check Indexation
If a page is not indexed, it cannot appear in search results. Period. Verify that your important pages are in Google's index.
- Use the
site:yourdomain.comsearch operator in Google to see how many pages are indexed. - Compare that number to the pages in your sitemap. A large gap means indexation problems.
- Check for accidental noindex tags on pages you want ranked.
- Review your robots.txt with the robots.txt checker to ensure no rule blocks important pages.
Step 3: Validate Your XML Sitemap
Your XML sitemap tells search engines which pages exist and which ones to prioritize. A broken sitemap wastes crawl budget and delays indexing.
- Ensure the sitemap is referenced in robots.txt.
- Verify every URL in the sitemap returns a 200 status code.
- Remove noindexed, redirected, and canonicalized pages from the sitemap.
- Keep the sitemap under 50,000 URLs and under 50MB uncompressed.
Step 4: Audit Redirects
Redirect chains and mixed redirect types waste link equity, slow crawlers, and degrade user experience.
- Run the redirect checker on every migrated URL.
- Flatten redirect chains to a single hop. A chain of three or more 301s should become one redirect.
- Ensure permanent moves use 301 redirects, not 302s.
- Fix any redirect loops that return a too-many-redirects error.
Step 5: Review SSL and Security
HTTPS is a confirmed ranking signal. An expired certificate or mixed content warnings erode trust with both users and search engines.
- Verify your SSL certificate is valid and not expired.
- Check for mixed content (HTTP resources loading on an HTTPS page).
- Ensure all internal links point to HTTPS URLs, not HTTP.
- Implement HSTS headers to force HTTPS for returning visitors.
Step 6: Test Page Speed and Core Web Vitals
Site speed is a confirmed ranking factor. Google measures three Core Web Vitals: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS).
- Run the pagespeed checker on your top 10 pages.
- Target LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1.
- Test on a throttled mobile connection, not just a fast desktop network.
- Use the bulk Core Web Vitals checker to test multiple URLs at once.
Step 7: Check Mobile Usability
Google uses mobile-first indexing, so your mobile experience directly affects rankings. A page that looks great on desktop but fails on mobile will not rank well.
- Check for tap targets that are too close together.
- Ensure text is readable without zooming.
- Verify no content is hidden behind interstitials or popups.
- Use the pagespeed checker to simulate mobile load conditions.
Step 8: Audit Structured Data
Invalid structured data does not help and can trigger warnings in Search Console. Valid markup can unlock rich results that increase visibility and click-through rate.
- Review structured data with the schema validator.
- Ensure you only mark up content that is actually visible on the page.
- Fix any parsing errors or warnings before requesting validation in Search Console.
Step 9: Review Internal Links
Internal links help crawlers discover pages and distribute authority across your site. Orphan pages (pages with no internal links pointing to them) are hard for search engines to find.
- Map your internal link structure. Every important page should be linked from at least 3 other pages.
- Fix broken internal links that return 404 errors.
- Use the broken links checker to find dead links across your site.
- Ensure anchor text is descriptive and includes relevant keywords naturally.
Prioritize Your Fixes
Audit findings are only valuable if you act on them. Prioritize by impact: indexability issues first (noindex, blocked robots.txt), then crawl errors (404s, redirect chains), then speed and structured data. Document what you fix, re-test after each change, and track how rankings respond.
Run the free SEO quick audit monthly to catch new issues early. A healthy technical foundation makes every other SEO effort more effective.