Technical SEO underpins your website’s visibility. Crawling, indexing, redirects, or page performance issues can keep otherwise good content from ranking.

This technical SEO checklist covers 30 checks, from essential fixes to advanced improvements, so you know what to prioritise first.

How to Use This Technical SEO Checklist

Not every technical SEO issue has the same impact. Start with critical issues that can block crawling, indexing, or rankings. Then move to important issues and advanced improvements.

Critical Technical SEO Checks

Check these issues first because they can directly affect whether Google can access, understand, and index your website.

1. Check HTTPS

Make sure every page and asset loads over HTTPS. Fix mixed content issues involving images, CSS, JavaScript, or other resources.

2. Check Mobile-First Indexing

Google primarily uses the mobile version of a website for indexing and ranking.

Check that:

• Mobile and desktop content are consistent.

• Text is easy to read.

• Tap targets are large enough.

• Important content is not hidden behind intrusive interstitials.

3. Fix Valuable 404 Pages

Find 404 pages in Google Search Console. Redirect valuable URLs with backlinks or useful internal links to the most relevant live page.

Remove or fix internal links pointing to unnecessary 404 URLs.

4. Check robots.txt

Make sure robots.txt does not accidentally block important sections of your website.

Pay particular attention to:

• Disallow: /

• Important CSS and JavaScript files

• Important page directories

5. Keep the XML Sitemap Clean

Your XML sitemap should contain only indexable URLs.

Exclude:

• Noindex pages

• 404 pages

• Redirect URLs

• Unnecessary paginated URLs

Submit the sitemap through Google Search Console.

6. Remove Redirect Chains

Avoid situations where:

Page A → Page B → Page C

Instead, redirect Page A directly to Page C.

This reduces unnecessary hops and makes crawling more efficient.

7. Check Canonical Tags

Use self-referencing canonical tags on important pages and point duplicate or near-duplicate URLs to the preferred version.

Check common variations such as:

• HTTP vs HTTPS

• www vs non-www

• Trailing slashes

• URL parameters

8. Check Core Web Vitals

Monitor the three Core Web Vitals:

Common fixes include image optimisation, better caching, specifying image dimensions, and reducing layout shifts.

Crawling vs Indexing: What Is the Difference?

Crawling and indexing are different processes.

Crawling means Google accesses a URL. Indexing means Google decides whether that page should be stored and shown in search results.

So, a page being crawled does not guarantee that it will be indexed.

If Google Search Console shows an “Indexed, though blocked by robots.txt” or similar access issue, use the URL Inspection tool to check what Googlebot can actually access.

Does Crawl Budget Matter for Every Website?

Usually, no.

Google has indicated that crawl budget becomes a meaningful concern mainly for very large websites, such as sites with around 1 million unique pages updated weekly or 10,000 pages changing daily.

For most small and mid-sized websites, focus first on:

• Indexability

• Internal linking

• Content quality

• Duplicate URLs

• Server performance

Do Not Serve Separate Markdown Pages to AI Crawlers

Some websites have started serving separate Markdown versions of pages to AI crawlers such as GPTBot and ClaudeBot.

This is not recommended.

Google and Microsoft have both pushed back against this approach because search engines can process standard HTML and may crawl both versions to check whether the content matches. Serving significantly different content to bots and users can also create cloaking risks.

The better approach: use clean, semantic HTML that works for users, search engines, and AI crawlers.

Important Technical SEO Checks

These issues may not completely block rankings, but they can affect performance, crawling, indexation, and user experience.

9. Improve Page Speed

• Compress images.

• Use WebP where appropriate.

• Enable Gzip or Brotli.

• Minify CSS and JavaScript.

• Use browser caching.

10. Add Relevant Structured Data

Use schema markup where it accurately represents the page, such as:

• Article or BlogPosting

• Product

• BreadcrumbList

• FAQ where eligible

Schema does not directly improve rankings, but eligible rich results can improve search visibility and CTR.

11. Audit Internal Links

Check for:

• Broken internal links

• Orphan pages

• Unnecessary redirects

• Important pages with very few internal links

12. Fix Duplicate Content

Identify duplicate and near-duplicate pages created by:

• Tags

• Filters

• Search pages

• URL parameters

• CMS archives

Use canonical or noindex where appropriate.

13. Keep Important Pages Close to the Homepage

Important pages should ideally be reachable within 2 to 3 clicks from the homepage through a logical site structure.

14. Review Server Logs

Server logs can show:

• Which URLs Googlebot crawls

• How often they are crawled

• Whether low-value pages receive excessive crawl activity

Use this information to improve internal linking and crawl controls where needed.

15. Keep URLs Clean

Use short, descriptive URLs with clear words separated by hyphens.

Avoid unnecessary parameters and complicated URL structures.

If a URL changes, redirect the old URL to the new one.

16. Implement Hreflang Correctly

For multilingual or multi-country websites, use hreflang to help Google understand which version should appear for each audience.

17. Check JavaScript Rendering

For React, Vue, Angular, and other JavaScript-heavy websites, use Google Search Console’s URL Inspection tool to confirm that Google can see the important content.

18. Handle Pagination Properly

Do not automatically noindex useful paginated pages.

Make sure paginated pages are crawlable and contain unique content where appropriate.

Advanced Technical SEO Checks

Once the core technical issues are fixed, move to these additional improvements.

Technical SEO Tools You Should Use

You do not need dozens of tools to run a technical SEO audit. A small, reliable stack can cover most requirements.

For larger websites, continuous monitoring can help identify technical problems between full audits.

Wrapping Up

Technical SEO is not a one-time task. Websites change constantly, and new issues can appear after redesigns, CMS updates, migrations, or content changes.

Start with the 8 critical technical SEO checks, then work through the important and advanced checks regularly. The goal is simple: make sure search engines can crawl, understand, index, and efficiently access your most valuable pages.

Once the technical foundation is strong, you can focus on the next layer of organic visibility. For AI search specifically, see our guide on how to rank in Google AI Overviews.