What Is a Technical SEO Audit?
A technical SEO audit is a systematic evaluation of your website's technical infrastructure to identify issues that prevent search engines from effectively crawling, indexing, and ranking your pages. It's the diagnostic phase that precedes any effective SEO strategy — without it, you're optimizing blind.
A comprehensive audit examines 150+ technical signals spanning crawlability, indexation, site architecture, page speed, mobile usability, structured data, HTTPS security, and JavaScript rendering. The output is a prioritized list of issues ranked by their potential impact on your organic search performance.
If you're wondering how to do a technical SEO audit effectively, this guide walks you through the full process — tools, methodology, and what to actually look for at each step.
Step 1: Set Up Your Audit Tools
Before you crawl a single URL, you need the right tools configured. Here's the essential technical SEO audit toolkit:
Screaming Frog SEO Spider — The industry standard for on-demand site crawling. The paid version (£199/year) unlocks JavaScript rendering, custom extraction, and scheduled crawls.
Google Search Console — Your most valuable data source. GSC shows you what Google actually sees: which pages are indexed, crawl errors, Core Web Vitals field data, and which queries drive impressions.
PageSpeed Insights / Lighthouse — For Core Web Vitals and performance analysis. Always check both mobile and desktop, and look at field data (CrUX) alongside lab scores.
Sitebulb — Excellent for visualizing site architecture and crawl depth. The crawl maps make it easy to spot deep page hierarchies and orphaned content.
Ahrefs / SEMrush — For backlink analysis, redirect chain detection, and competitor benchmarking. Also useful for comparing crawled pages against indexed pages.
Log File Analyzer (Screaming Frog Log Analyzer or Botify) — For understanding how Googlebot is actually crawling your site, not just how you expect it to.
Step 2: Crawl Your Site
Configure Screaming Frog to crawl your site with JavaScript rendering enabled (Configuration → Spider → Rendering → JavaScript). Set your crawl speed to a level your server can handle (typically 5–10 requests/second for most sites).
Start with a configuration that includes: - Respecting robots.txt: Yes (see how Googlebot sees your site) - Check source code: Yes (catches noindex tags in raw HTML vs. rendered HTML) - Extract: H1, H2, canonical tag, meta robots, hreflang, og:title, schema types
Once the crawl completes, export the full URL list and begin your analysis. For large sites (10,000+ URLs), use Screaming Frog in list mode against a URL export from Google Search Console to focus on indexed pages first.
Key crawl statistics to note:
Step 3: Audit Indexation
Open Google Search Console → Pages report. Compare the number of pages Google has indexed against the number of pages you want indexed. Common discrepancies to investigate:
Indexed but shouldn't be: Pagination URLs (?page=2), URL parameter variants, staging URLs, internal search results pages, or thin content pages that should be consolidated.
Should be indexed but aren't: Key service pages, product pages, or blog posts showing "Crawled - currently not indexed" or "Discovered - currently not indexed" status. These often indicate quality signals issues, thin content, or internal linking problems.
Noindex check: Export all pages with noindex meta tags from Screaming Frog and verify every single one should be excluded from the index. Accidental noindex tags on important pages are one of the most damaging and easy-to-miss technical SEO errors.
Robots.txt audit: Review your robots.txt file manually. Check if any important resources (CSS, JavaScript, image directories) are being blocked — this can prevent Googlebot from rendering your pages correctly.
Step 4: Assess Site Architecture & Crawl Depth
A flat site architecture (3 clicks or fewer from homepage to any important page) is significantly better for SEO than a deep hierarchy. Use Screaming Frog's crawl depth report or Sitebulb's architecture visualization to identify:
Check your XML sitemaps: Do they include only canonical, indexable 200-status URLs? Many sites have sitemaps full of redirect URLs, noindex pages, and 404s — which wastes Googlebot's attention.
Step 5: Evaluate Core Web Vitals
In Google Search Console, navigate to Experience → Core Web Vitals. Review field data for both mobile and desktop. Pages with "Poor" LCP, INP, or CLS need immediate attention.
For page-level diagnosis, run PageSpeed Insights on your most important pages — homepage, category pages, key landing pages. Note:
Read our complete Core Web Vitals optimization guide for specific fix techniques.
Step 6: Check Structured Data
Use Google's Rich Results Test and Schema Markup Validator on a representative sample of pages across your site. Common schema issues to look for:
Check Search Console's Enhancement reports — they show which schema types Google has detected and whether they have errors or warnings.
Step 7: Document, Prioritize & Report
Every technical SEO audit should conclude with a prioritized issue list — not a 200-page report dump. Triage every issue by:
Priority 1 (Critical): Issues that are actively preventing indexation or causing significant ranking loss. Examples: noindex on important pages, robots.txt blocking Googlebot, canonical pointing to wrong URL.
Priority 2 (High): Issues that are diluting rankings or preventing rich results. Examples: duplicate title tags, missing structured data, Core Web Vitals failures on high-traffic pages.
Priority 3 (Medium): Issues that create inefficiency but aren't causing immediate harm. Examples: redirect chains, orphan pages, non-optimized sitemaps.
Priority 4 (Low): Best-practice improvements. Examples: missing alt text on decorative images, minor schema enhancements.
Present findings in a format your team can act on. See our technical SEO audit checklist for a complete list of items to check. If you'd rather have our team conduct the audit professionally, get in touch.