How to Do a Technical SEO Audit Using Your Analytics Data

By Emily Redmond, Data Analyst at Emilytics · April 2026

TL;DR: Technical SEO audit finds crawl errors, broken pages, indexation problems, and slow pages using GSC and site audit tools. Fix these to improve rankings and user experience.

What Is a Technical SEO Audit?

A technical SEO audit checks if your site is:

Crawlable: Can Googlebot crawl all pages?
Indexable: Are pages in Google's index?
Mobile-friendly: Does it work on mobile?
Fast: Do pages load quickly?
Secure: Is it HTTPS?
Structured properly: Is markup correct?

These aren't content issues. They're technical foundation issues.

Step 1: Crawl Errors in Google Search Console

Check Coverage Report

In GSC:

Go to Coverage.
You'll see four categories:
- Error - Pages Google couldn't crawl or index
- Valid - Pages successfully indexed
- Valid with warnings - Indexed but with issues
- Excluded - Pages Google didn't index (by choice)

Focus on Errors:

Click on Error. You'll see:

Pages with 404 errors (page not found)
Pages with 403 errors (server denied access)
Pages with 5xx errors (server error)
Crawl timeout (page took too long)

Action: Fix 404s by updating links or redirecting. Fix 5xx errors (server issue). Fix timeouts (page is too slow).

Check Crawl Stats

Go to Settings > Crawl Stats.

You'll see:

Requests per day - How much Google is crawling
Pages crawled per day - Pages per crawl
Data downloaded per day - KB per crawl
Time spent downloading - Average page load time

What to look for:

If Time spent downloading is increasing, your pages are getting slower. Fix page speed.

If Requests per day are dropping, Google is crawling less. Investigate why (errors, slow pages, or crawl budget waste).

Step 2: Mobile-Friendliness

Run Mobile-Friendly Test

Go to Google Mobile-Friendly Test.
Enter your homepage.
Test shows: Is your site mobile-friendly?

Issues it checks:

Viewport not configured (page doesn't scale on mobile)
Text too small (unreadable on mobile)
Clickable elements too close (hard to tap)
Flash used (not supported on mobile)

Action: Fix any issues. Most are quick wins.

Check GSC Mobile Usability Report

In GSC:

Go to Enhancements > Mobile Usability.
See which pages have mobile issues.

This is higher-level than the Mobile-Friendly Test. It shows:

Clickable elements too close together
Text too small
Content wider than screen

Action: Use a mobile-responsive design. Test on real devices.

Step 3: Page Speed Audit

Slow pages hurt rankings (since 2021) and user experience.

Check Core Web Vitals

In GSC:

Go to Enhancements > Core Web Vitals.
You'll see:
- Largest Contentful Paint (LCP) - How long until main content loads (target: <2.5 seconds)
- First Input Delay (FID) - How long until page responds to user input (target: <100ms)
- Cumulative Layout Shift (CLS) - How much does layout shift as content loads (target: <0.1)

Red = bad. Yellow = okay. Green = good.

Action: Pages with red need optimization. Common fixes:

Compress images
Minimize CSS/JavaScript
Use a CDN
Enable caching
Upgrade hosting

Use PageSpeed Insights

Go to Google PageSpeed Insights.
Enter a page URL.
You'll see:
- Mobile score (0–100)
- Desktop score (0–100)
- Opportunities (what to fix)
- Diagnostics (what's slow)

PageSpeed gives concrete recommendations. Follow them.

Step 4: Structured Data & Rich Results

Structured data helps Google understand your content.

Check Rich Results

In GSC:

Go to Enhancements > Rich Results.
See which pages have rich result eligibility (recipes, reviews, job postings, etc.).

If you have zero rich results but should have them (e.g., recipes), add schema markup.

Validate Structured Data

Go to Google's Rich Results Test.
Enter a page URL.
Validation shows:
- Found structured data? (yes/no)
- What type? (Article, Product, Review, etc.)
- Issues? (errors or warnings)

Action: If errors, fix schema markup. If no structured data, consider adding it.

Step 5: Indexation Audit

Check What's Indexed

In GSC:

Go to Coverage.
Note total "Valid" pages (indexed).

Compare to:

Your sitemap (how many pages should be indexed?)
Your internal page count

Example:

Your site has 500 pages. Sitemap lists 500. GSC shows 350 indexed.

Gap: 150 pages not indexed. Investigate why.

Common reasons:

Pages are too new (wait 4 weeks)
Pages have noindex tag (remove if intentional)
Pages are blocked in robots.txt (unblock if needed)
Pages are low-quality or duplicate (okay to not index)

Step 6: Check for Duplicate Content

Use Search Operators

In Google Search, search:

site:yoursite.com [your main page]

How many results? If >1, you have duplicates.

Example:

site:emilytics.io "SEO analytics"

If this returns 5 pages, you have 5 pages about SEO analytics. Potential cannibalization.

Use GSC Exclude Report

Check which pages are excluded due to being "Duplicate" in GSC Coverage.

Step 7: Site Security (HTTPS)

Check SSL Certificate

All pages should be HTTPS, not HTTP.

Visit your homepage
Check the URL. Is it https:// ?

If not, get an SSL certificate (most hosts offer free SSL now).

Check for Mixed Content

Sometimes pages load over HTTPS but include images/scripts from HTTP (mixed content).

In your browser:

Go to a page
Press F12 (developer tools)
Check Console for warnings about "mixed content"

Fix: Update all internal links to HTTPS.

Technical SEO Audit Checklist

Common Technical Issues

Issue	Impact	Difficulty
404 errors	High (broken pages)	Low (easy fix)
Slow pages	High (rankings + UX)	High (often complex)
Mobile unfriendly	High (poor UX)	Medium (CSS fixes)
Noindex pages	Medium (lost traffic)	Low (remove tag)
Duplicate content	Medium (wasted crawl)	Medium (canonicalization)
Bad schema	Low (no rich results)	Low (add markup)

💡 Emily's take: Technical SEO often has the highest ROI. One crawl error affecting 100 pages. One mobile issue affecting traffic. One speed improvement helping rankings. These fix entire problems, not just one page. Always audit technical first.

Tools for Technical Audit

Free: Google Search Console, PageSpeed Insights, Screaming Frog (limited)
Paid: SEMrush, Ahrefs, Sitebulb

For most sites, GSC + PageSpeed Insights + Screaming Frog is enough.

Frequently Asked Questions

Q: How often should I audit technically?

A: Quarterly. After every major site change, immediately.

Q: What if I have 500 errors?

A: Prioritize. Fix high-traffic pages first. Then systematically fix others.

Q: Does technical SEO matter as much as content?

A: Both matter. Broken technical foundation limits ranking potential. Good technical allows content to rank.

Q: Should I fix all issues or prioritize?

A: Prioritize. Fix high-impact issues first (crawl errors, mobile, speed). Low-impact issues (schema warnings) can wait.

The Bottom Line

A technical SEO audit finds and fixes the foundation issues that hold back your rankings.

Run through GSC and PageSpeed Insights quarterly. Fix errors systematically. Most are quick wins.

Technical SEO might not be sexy. But it's the difference between a site that ranks and one that doesn't.

Emily Redmond is a data analyst at Emilytics — the AI analytics agent watching your data around the clock. 8 years experience. Say hi →