Elena Soto
Technical SEO Strategist
“A prioritized technical SEO checklist - the 20 most impactful fixes, from indexing errors to schema markup, with how to check and resolve each.”
Executive Summary (Key Takeaways)
- Why Technical SEO First: Content and backlink strategies underperform on a technically broken website. Technical SEO clears the barriers that prevent Google from crawling, indexing, and correctly evaluating your content - it is the prerequisite for everything else to work.
- The Priority Order: The 20 items below are organized from highest-impact (indexing and crawlability) to medium-impact (performance and schema). Fix in order - item 1 is useless if item 1 is broken.
- The Free Tools: Most of these checks can be performed with Google Search Console (free), Google PageSpeed Insights (free), and a basic View Source inspection. You do not need expensive tools to diagnose most technical issues.
- The 80/20 Rule: Items 1–8 on this checklist account for approximately 80% of the technical SEO value. If you have limited time, prioritize those eight first.
Technical SEO Checklist: 20 Things to Fix on Your Site
Technical SEO is the practice of ensuring your website's infrastructure is optimized for search engine crawling, indexing, and ranking. It covers everything except content and backlinks: site speed, indexing configuration, schema markup, mobile usability, HTTPS security, and correct URL structures. A technically clean website maximizes the impact of every content and link-building effort. A technically broken website limits them regardless of quality.
Work through this checklist systematically. Each item includes how to check it and the first step toward fixing it.
🔴 Priority Group 1: Crawlability and Indexing (Fix First)
1. Verify Your Site Is Indexed by Google
Check this first, before anything else. An unindexed website is invisible to Google regardless of any other optimization work. Type
site:yourdomain.cominto Google. If zero results appear, your website has an indexing failure that must be resolved before any other SEO effort can produce results.
How to fix: Set up Google Search Console, verify ownership, and use the URL Inspection tool to diagnose the indexing failure. Common causes: robots.txt blocking, noindex tags, or lack of any external links for Googlebot to follow.
2. Check Your Robots.txt File
Your robots.txt file tells search engine crawlers which pages they can and cannot access. A misconfigured robots.txt that blocks crawlers from important pages - or blocks the entire site - is one of the most common technical SEO disasters, particularly after website migrations.
How to check: Visit yourdomain.com/robots.txt in your browser. Look for any Disallow: / rules under User-agent: *. A site-wide block looks like: Disallow: /
How to fix: Change Disallow: / to Disallow: (empty value means nothing is blocked). Submit an updated sitemap in Search Console after correcting.
3. Confirm No Unintended Noindex Tags
A noindex meta tag on a page tells Google not to include it in search results. This is correct on admin pages, thank-you pages, and tag archives - but catastrophic on service pages or blog posts you want to rank.
How to check: In Google Search Console's URL Inspection tool, paste any important page URL. If it says "URL is not on Google," check whether a noindex tag is the cause. Alternatively, View Source on the page and search for noindex.
How to fix: Remove the <meta name="robots" content="noindex"> tag from any page you want Google to index.
4. Submit Your XML Sitemap
An XML sitemap is a file that lists all the important pages on your website, helping Google discover and index them efficiently. Without a sitemap, Google must discover pages by following links - a slower, less reliable process, particularly for new sites.
How to check: Visit yourdomain.com/sitemap.xml in your browser. If a structured XML file appears, your sitemap exists. Then check Search Console → Sitemaps to see if it is submitted.
How to fix: Most CMS platforms (WordPress, Next.js, Webflow) generate sitemaps automatically. If yours does not, plugins like Yoast SEO (WordPress) generate and submit them. Submit the sitemap URL in Google Search Console.
5. Fix All Broken Internal Links (404 Errors)
A broken internal link - one that points to a page that no longer exists - wastes crawl budget and creates a dead end in your site's link graph. Google's crawler follows every internal link; reaching a 404 page from an important page signals poor site maintenance.
How to check: Google Search Console → Coverage → "Excluded" → "Not found (404)" shows pages generating 404 errors. Free tools like Screaming Frog's SEO Spider crawl your entire site and flag broken links.
How to fix: Either restore the deleted page, redirect the broken URL to the most relevant existing page using a 301 redirect, or update the internal link to point to the correct destination.
🟠 Priority Group 2: HTTPS, Mobile, and Performance
6. Ensure Full HTTPS (No Mixed Content)
Every page on your website should be served over HTTPS. Mixed content - where a page loads over HTTPS but requests resources (images, scripts) over HTTP - creates browser security warnings and is a ranking signal. Google has used HTTPS as a ranking signal since 2014.
How to check: Look for the padlock icon in your browser's address bar. If you see "Not Secure" or a broken padlock, there is an HTTPS issue. Developers can use browser DevTools (Console tab) to identify mixed content warnings.
How to fix: Ensure all resources (images, scripts, stylesheets) are loaded via HTTPS URLs. Your hosting provider can typically enable SSL at no extra cost via Let's Encrypt.
7. Fix Mobile Usability Issues
Google uses mobile-first indexing - it evaluates and ranks websites based primarily on their mobile version. A website with mobile usability errors (text too small, clickable elements too close together, content wider than the screen) is ranked based on those deficiencies.
How to check: Google Search Console → Experience → Mobile Usability. Any errors listed here are actively affecting your ranking. Also test at search.google.com/test/mobile-friendly.
How to fix: Errors are typically caused by: non-responsive design (use a responsive CSS framework), text too small (minimum 16px body text), tap targets too small (minimum 44×44px), or viewport not configured (add <meta name="viewport" content="width=device-width, initial-scale=1">).
8. Improve Core Web Vitals Scores
Core Web Vitals - Largest Contentful Paint (LCP), Interaction to Next Paint (INP), Cumulative Layout Shift (CLS), and Time to First Byte (TTFB) - are direct Google ranking factors since the 2021 Page Experience update. Failing any of these metrics creates a measurable ranking disadvantage.
How to check: Google Search Console → Experience → Core Web Vitals shows field data from real users. pagespeed.web.dev gives lab data with specific recommendations.
Key targets:
- LCP: under 2.5 seconds
- INP: under 200ms
- CLS: under 0.1
- TTFB: under 200ms
For detailed fixes, see our full guide on why your website is so slow and how to fix it.
9. Optimize Page Load Speed
Page speed is correlated with both Core Web Vitals performance and user bounce rates. The most impactful speed improvements for most business websites: image compression and format conversion (WebP), browser caching, CDN implementation, and elimination of unused JavaScript and CSS.
Quick wins (no developer needed):
- Compress images using Squoosh (free, browser-based)
- Convert images to WebP format
- Install WP Rocket or W3 Total Cache (WordPress) for caching
- Enable Cloudflare's free CDN
🟡 Priority Group 3: URL Structure and Canonicalization
10. Fix Duplicate Content and Canonical Tags
Duplicate content occurs when the same or very similar content is accessible via multiple URLs. This confuses Google about which version to rank and can dilute your page's ranking authority across multiple URLs. Canonical tags tell Google which version of a page is the "official" one to index and rank.
Common duplicate content scenarios:
http://andhttps://versions of the same pagewww.and non-www.versions- URL parameters creating multiple versions:
?page=1,?sort=asc - Paginated content without proper canonical configuration
How to check: View Source on any page and search for <link rel="canonical". The canonical URL should match the page's "preferred" URL exactly.
11. Implement Proper Redirect Chains
A redirect chain occurs when URL A redirects to URL B which redirects to URL C. Each redirect in a chain loses a small amount of link equity and adds latency. Chains of 3+ redirects should be collapsed to direct redirects (A→C) wherever possible.
How to check: Free redirect chain checker tools (e.g., redirect-checker.org) trace the redirect path for any URL. Screaming Frog identifies redirect chains automatically.
12. Configure Clean URL Structures
URL structure signals page topic to both Google and users. Clean, descriptive URLs outperform cryptic ones:
/blog/technical-seo-checklistis better than/post?id=2847&cat=4. URLs should use hyphens (not underscores), be lowercase, and avoid unnecessary parameters.
🟢 Priority Group 4: Schema Markup and Structured Data
13. Implement LocalBusiness Schema on Homepage
LocalBusiness JSON-LD schema on your homepage tells Google exactly who your business is, what it does, where it is located, and how to contact it - in structured, machine-readable data. This is essential for local search visibility and AI search citation. It is also the fastest schema win available for most business websites.
Implementation template:
{
"@context": "https://schema.org",
"@type": "LocalBusiness",
"name": "Your Business Name",
"description": "Brief description of services",
"url": "https://yourdomain.com",
"telephone": "+44-XXXX-XXXXXX",
"address": {
"@type": "PostalAddress",
"streetAddress": "Your Street",
"addressLocality": "Your City",
"addressRegion": "Your County",
"postalCode": "Your Postcode"
}
}
14. Add Article Schema to Every Blog Post
Article JSON-LD schema on blog posts signals to Google and AI engines that the page is a published editorial piece with a specific author, publish date, and topic. This is a prerequisite for AI Overviews to consider citing your content.
For a complete guide to schema implementation and its impact on AI search visibility, see our guide on how to optimize your business for AI Overviews and ChatGPT.
15. Implement FAQPage Schema on Key Pages
FAQPage JSON-LD schema marks up the questions and answers on a page in a format Google can extract for rich snippets (bold, expandable Q&A in search results) and AI Overview citations. Pages with FAQPage schema earn significantly more real estate in search results.
16. Validate All Schema With Google's Rich Results Test
Schema markup with syntax errors is as valuable as no schema at all - Google will not process malformed structured data. Validate every schema implementation using Google's Rich Results Test (search.google.com/test/rich-results) before publishing.
🔵 Priority Group 5: Content and Internal Linking
17. Fix Thin Content Pages
Pages with fewer than 300 words of meaningful, original content are categorized as "thin content" and suppressed by Google's Helpful Content System. Thin pages - especially tag archives, category pages without descriptions, or stub service pages - can drag down the overall quality assessment of your entire domain.
How to check: Google Search Console → Performance → Pages sorted by impressions. Any page with high impressions but very low clicks may have thin content. Screaming Frog's Word Count filter identifies short pages.
18. Optimize Internal Linking Structure
Internal links (links between pages on your own website) distribute "link equity" from authoritative pages to others and help Google understand your site's topic hierarchy. A well-structured internal linking strategy - where your most important pages receive links from multiple other pages on the site - significantly improves those pages' ranking potential.
For every new page published, add 2–3 contextual internal links to it from existing relevant pages, and add links from the new page to the most relevant existing pages.
19. Optimize Title Tags and Meta Descriptions
Title tags (the text in the browser tab and in the Google search result headline) should include your primary keyword, be under 60 characters, and clearly describe the page's content. Meta descriptions (the text below the headline in search results) should include your primary keyword, be under 155 characters, and provide a compelling reason to click.
Common title tag mistakes:
- Using the same title tag on multiple pages (duplicate titles)
- Title tags longer than 60 characters (Google truncates them)
- Missing the primary keyword
- Using just the company name with no descriptive text
20. Fix Image Alt Text
Alt text is the text description of an image, read by screen readers and indexed by Google as a signal about the image's content and the page's topic. Images without alt text are missed optimization opportunities. Alt text should be descriptive, specific, and naturally include relevant keywords where appropriate.
How to check: Screaming Frog's image export identifies images with missing or empty alt attributes. Google Search Console does not directly surface this issue.
How to write good alt text: Describe the image specifically. alt="web design agency team reviewing Next.js code on dual monitors" is better than alt="team photo" or alt="web design".
Frequently Asked Questions
How often should I run a technical SEO audit?
A light technical review (checking Search Console for new errors, running a pagespeed check) should happen monthly. A comprehensive crawl-based audit covering all 20 items above should be run quarterly, and always before and after any significant website change (new CMS, URL restructuring, new content management practices).
Do I need a developer to fix technical SEO issues?
Approximately half of the issues on this checklist can be addressed without developer involvement - particularly robots.txt checks, Search Console monitoring, sitemap submission, image compression, and hosting/CDN changes. The more complex fixes - canonicalization configuration, redirect chain management, schema implementation, and Core Web Vitals performance engineering - typically require a developer.
What is the most impactful single technical SEO fix?
If your site is not indexed, that is the most impactful fix (it is binary - nothing else works until this is resolved). For already-indexed sites, improving Core Web Vitals scores typically produces the largest measurable ranking improvement because it affects every page simultaneously and is a direct ranking signal.
Can technical SEO issues cause a ranking penalty?
Some technical issues are ranking suppressors (they reduce rankings without being formal penalties) - slow load speeds, mobile usability failures, noindex tags on important pages. Formal penalties (Manual Actions in Search Console) are caused by guideline violations like purchased links or cloaking, not purely technical issues. The distinction matters because suppressors respond to technical fixes, while penalties require reconsideration requests.
How long does it take to see improvements after fixing technical SEO?
Google typically re-crawls and re-evaluates pages within 1 to 4 weeks of technical changes. Improvements to Core Web Vitals and indexing configuration can produce ranking changes visible in Search Console within 4 to 6 weeks. Comprehensive site-wide technical improvements sometimes show measurable ranking progress within 6 to 10 weeks.
The Bottom Line
Technical SEO is the unglamorous foundation of everything else. Content and backlinks are how you compete; technical SEO is how you remove the barriers to competing at all. Work through this checklist in priority order, and resolve items 1 through 8 before investing significantly in content or link building. A technically clean website amplifies every other SEO investment you make.
