Technical SEO audit checklist: 15 checks for any website

A technical SEO audit checks whether search engines can find, crawl, understand and index your pages. It isn’t about writing better content; it’s about removing the problems that stop good content from showing up. These 15 checks cover the issues that turn up on most websites, in a sensible order.

Work through them with a crawler tool, Google Search Console and your browser. Fix the problems that affect many pages or your most important pages first.

Crawling and status codes

1. Status codes

Every page you want in search should return 200 OK. Crawl your site and list anything else:

• 404 / 410: the page is gone. Fine if intended; fix any links pointing to it.
• 5xx: server errors. These are urgent, as repeated errors can lead Google to crawl less.
• Soft 404s: a “not found” message served with a 200 code. Search Console reports these under Pages.

2. Broken internal links

Links from your own pages to 404s waste crawling and frustrate visitors. Update each link to the right page, or remove it.

3. Redirects

Check for redirect chains (A → B → C) and loops. Point links and redirects straight at the final URL. Use 301 for permanent moves; a 302 says the move is temporary.

Indexability

4. Pages that should be indexed, are

In Search Console, open Indexing → Pages and read the reasons pages aren’t indexed. “Crawled – currently not indexed” and “Discovered – currently not indexed” often point to thin or low-value pages, or pages Google hasn’t got round to. See why your page isn’t on Google.

5. Accidental noindex

Look for <meta name="robots" content="noindex"> or an X-Robots-Tag: noindex header on pages you want indexed. A noindex left over from a staging site is a classic mistake after launch.

6. Canonical tags

Each indexable page should have a canonical pointing to itself (or to the preferred version if it’s a duplicate). Watch for canonicals pointing to redirects, 404s, or the home page on every URL. More in canonical tags explained.

On-page basics

7. Titles and H1s

Every page needs a unique, descriptive title and one clear H1. Flag pages with missing, empty or very long titles, and pages with no H1.

8. Duplicate titles

Many pages sharing one title (“Products”, “Home | Brand”) make it harder for Google and searchers to tell them apart. Common on paginated lists, tag pages and product variants.

9. Thin pages

Pages with very little unique content, such as empty category pages, auto-generated tag pages or near-copies of other pages, rarely help. Improve them, merge them, or noindex them. There’s no magic word count; judge whether the page is useful on its own.

Files that guide crawlers

10. XML sitemap

Your sitemap should list only indexable, canonical URLs returning 200. Submit it in Search Console and Bing Webmaster Tools, and reference it in robots.txt. Update it automatically when pages are added or removed.

11. robots.txt

Fetch /robots.txt and read it line by line. Make sure it doesn’t block important sections, or CSS and JavaScript files needed to render pages. Remember that robots.txt stops crawling, not indexing: a blocked page can still appear in results if other sites link to it.

User-agent: *
Disallow: /admin/
Sitemap: https://www.example.com/sitemap.xml

If you also manage AI crawlers in this file, check that a rule meant for one bot doesn’t accidentally apply to all of them.

Security and performance

12. HTTPS

Every page should load over HTTPS, and http:// versions should 301-redirect to it. Check for mixed content (images or scripts loaded over plain HTTP) and an expired or mismatched certificate. Also pick one host, www or not, and redirect the other.

13. Speed and Core Web Vitals

Test key templates (home, category, article, product) in PageSpeed Insights. Look at the field data first, if there is any. The “good” thresholds are LCP ≤ 2.5 s, INP ≤ 200 ms and CLS ≤ 0.1. See Core Web Vitals in plain words.

14. Mobile

Google mainly uses the mobile version of your pages for indexing. Open your key pages on a real phone: text should be readable without zooming, buttons easy to tap, and no content hidden or missing compared with desktop.

Site structure

15. Orphan pages

An orphan page has no internal links pointing to it. Search engines may find it only through the sitemap, if at all, and may treat it as unimportant. Compare your sitemap or CMS page list with the pages your crawler found by following links. Link each orphan from a relevant page, or retire it. See internal linking.

Doing the audit

A crawler does most of the heavy lifting. OZMAICO’s Site audit checks for broken pages and links, titles, H1s, thin pages, canonicals and orphan pages, and its Page speed tool runs PageSpeed Insights for you. Any reputable crawler will do; what matters is that you act on the results.

Run a full audit after a redesign, migration or CMS change, and a lighter one every few months.

In short

1. Status codes are 200 for pages you want indexed.
2. No broken internal links.
3. No redirect chains or loops.
4. Indexing report reviewed in Search Console.
5. No accidental noindex.
6. Canonicals point to the right, live URL.
7. Every page has a unique title and an H1.
8. Duplicate titles fixed.
9. Thin pages improved, merged or noindexed.
10. Sitemap lists only clean, indexable URLs.
11. robots.txt blocks nothing important.
12. HTTPS everywhere, one preferred host.
13. Core Web Vitals checked on key templates.
14. Pages work well on a phone.
15. No orphan pages.