Technical SEO is the foundation that everything else is built on. You can write the best content in the world, but if Google can't properly crawl, index, and understand your website, you'll never rank. Think of technical SEO as the engine under the hood — invisible to visitors, but absolutely critical to performance.

This checklist covers 25 technical SEO essentials organized by priority. Work through them systematically, and you'll have a technically sound website that gives your content the best possible chance of ranking.

Crawlability and Indexing (Items 1-7)

If Google can't find and access your pages, nothing else matters.

1. XML Sitemap

An XML sitemap tells Google about all the pages on your site. It should be automatically generated, include only indexable pages, and be submitted through Google Search Console. Keep it under 50,000 URLs and 50MB uncompressed. Submit at yourdomain.com/sitemap.xml.

2. Robots.txt

Your robots.txt file tells search engine crawlers which parts of your site they can and can't access. Check that you're not accidentally blocking important pages or resources (CSS, JavaScript, images). Access yours at yourdomain.com/robots.txt.

3. Crawl Budget Optimization

For larger sites (500+ pages), ensure Google isn't wasting crawl budget on unimportant pages. Block parameter URLs, archive pages, and admin pages from crawling. Use internal linking to prioritize important pages.

4. Index Coverage

Check Google Search Console's "Pages" report to see how many pages are indexed, which have errors, and which are excluded. Investigate and fix any indexing issues — especially for pages that should be ranking.

5. Canonical Tags

Canonical tags tell Google which version of a page is the "original" when duplicate or similar content exists. Every page should have a self-referencing canonical tag. Cross-domain duplicates need canonical tags pointing to the preferred version.

6. No Orphan Pages

Orphan pages are pages with no internal links pointing to them. Google may never discover these pages, or may consider them unimportant. Ensure every page you want indexed has at least one internal link from another page on your site.

7. Redirect Chains

Redirect chains (Page A → Page B → Page C) waste crawl budget and dilute link equity. Audit your redirects and ensure all point directly to the final destination. Replace chains with single 301 redirects.

Performance (Items 8-13)

8. Largest Contentful Paint (LCP) Under 2.5s

LCP measures how quickly the largest visible element loads. Common causes of poor LCP: unoptimized images, slow server response, render-blocking JavaScript. Preload your LCP image and ensure server response time (TTFB) is under 200ms.

9. Interaction to Next Paint (INP) Under 200ms

INP measures responsiveness — how quickly the page reacts when users interact. Minimize JavaScript execution, break up long tasks, and avoid heavy event handlers that block the main thread.

10. Cumulative Layout Shift (CLS) Under 0.1

CLS measures visual stability — how much the layout shifts during loading. Always set explicit width and height on images and videos. Reserve space for dynamic content (ads, embeds). Use CSS containment where appropriate.

11. Mobile Performance

Test your site specifically on mobile using PageSpeed Insights. Mobile scores are typically lower than desktop due to reduced processing power and slower connections. Aim for a mobile performance score of 80+.

12. Server Response Time

Time to First Byte (TTFB) should be under 200ms. If it's consistently higher, consider upgrading hosting, implementing server-side caching, or using a CDN to reduce latency.

13. Resource Compression

Enable Gzip or Brotli compression on your server. This compresses text-based files (HTML, CSS, JS) by 60-80% before sending them to the browser. Most modern servers support this with a simple configuration change.

On-Page Technical Elements (Items 14-19)

14. Unique Title Tags

Every page needs a unique, descriptive title tag under 60 characters. Include your primary keyword. Avoid generic titles like "Home" or "Services." Title tags are the #1 on-page ranking factor.

15. Meta Descriptions

Write unique meta descriptions for every important page. 150-160 characters. Include the target keyword and a compelling reason to click. While meta descriptions don't directly affect rankings, they significantly impact click-through rates from search results.

16. Heading Hierarchy

Use a logical heading structure: one H1 per page (your main topic), H2s for major sections, H3s for subsections. Don't skip levels (H1 → H3). Include keywords naturally in headings. This helps Google understand your content structure.

17. Image Optimization

Every image should have: descriptive alt text (for accessibility and SEO), appropriate file format (WebP/AVIF preferred), compressed file size, explicit dimensions, lazy loading for below-fold images. Large unoptimized images are the #1 cause of slow page loads.

18. Structured Data (Schema Markup)

Schema markup helps Google understand your content type and can generate rich snippets in search results. Essential schemas include:

Validate your schema using Google's Rich Results Test tool.

19. Open Graph and Twitter Card Tags

While not directly SEO, Open Graph (og:) and Twitter Card meta tags control how your pages appear when shared on social media. Include og:title, og:description, og:image, and og:url on every page. This improves click-through rates from social shares.

Security and Architecture (Items 20-25)

20. HTTPS Everywhere

Your entire site must be served over HTTPS. No exceptions. HTTP pages are flagged as "Not Secure" by browsers and penalized in search rankings. Ensure your SSL certificate is valid and auto-renewing. Redirect all HTTP URLs to their HTTPS equivalents.

21. Clean URL Structure

URLs should be: human-readable, descriptive, lowercase, use hyphens (not underscores), and as short as possible while remaining descriptive. Avoid parameters, session IDs, and unnecessary folders. Good: /services/web-development/ Bad: /page.php?cat=3&id=47

22. Proper 404 Handling

Create a custom 404 page that helps lost visitors find what they're looking for — include search functionality, popular pages, and navigation. Monitor 404 errors in Search Console and set up redirects for any URLs receiving significant traffic.

23. International/Language Handling

If your site serves multiple languages or regions, implement hreflang tags correctly. Each language version should reference all other versions, including itself. This prevents duplicate content issues across language variants.

24. Mobile-First Architecture

Since Google uses mobile-first indexing, your mobile site is the primary version Google evaluates. Ensure: all content present on desktop is also on mobile, structured data is on the mobile version, images have appropriate alt text on mobile, and meta tags (title, description, robots) are identical across versions.

25. Site Architecture and Internal Linking

Your site should follow a logical hierarchy where every page is reachable within 3 clicks from the homepage. Use breadcrumbs for navigation and user orientation. Create topic clusters with pillar pages linking to related content. Distribute internal links strategically to pass authority to your most important pages.

How to Audit Your Technical SEO

Run a full technical audit using these tools:

  1. Google Search Console: Free. Monitors indexing, coverage errors, Core Web Vitals, and mobile usability
  2. Google PageSpeed Insights: Free. Tests performance and provides specific optimization recommendations
  3. Screaming Frog: Desktop crawler that identifies technical issues across your entire site (free for up to 500 URLs)
  4. Ahrefs/SEMrush Site Audit: Comprehensive technical SEO audit with prioritized recommendations
  5. Google Rich Results Test: Validates your structured data implementation

Technical SEO isn't glamorous, but it's the difference between content that ranks and content that Google never sees. Fix the foundation, and everything you build on top performs better.

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Technical SEO SEO Checklist Core Web Vitals Schema Markup Site Audit Web Performance