Technical SEO Checklist 2026: 15 Things Your Website Must Have

Great content on a broken website won’t rank

You could write the best article on the internet. But if your website loads in 8 seconds, isn’t mobile-friendly, or confuses search engine crawlers — nobody will ever see it.

Technical SEO is the foundation. It’s not glamorous. But without it, nothing else works. Here are the 15 things your website must have right in 2026 — in order of impact.

Core Web Vitals (items 1-3)

Google uses Core Web Vitals as a direct ranking factor. These three metrics measure real user experience on your site.

1. Largest Contentful Paint (LCP) under 2.5 seconds

LCP measures how long it takes for the main content on your page to load. The biggest element the user sees — usually a hero image, heading, or text block.

How to fix slow LCP:

• Compress and properly size images (use WebP format, not PNG/JPG)
• Use a CDN (Content Delivery Network) to serve assets from nearby servers
• Minimize render-blocking CSS and JavaScript
• Implement lazy loading for images below the fold
• Preload your largest content element

Check it: Google PageSpeed Insights gives you your exact LCP score for both mobile and desktop.

2. Interaction to Next Paint (INP) under 200ms

INP replaced First Input Delay in 2024. It measures how quickly your page responds when someone clicks a button, taps a link, or types in a field. Anything over 200ms feels sluggish.

How to fix slow INP:

• Break up long JavaScript tasks (nothing should block the main thread for more than 50ms)
• Use web workers for heavy computations
• Defer non-critical third-party scripts (chat widgets, analytics, social embeds)
• Minimize DOM size — pages with 1,500+ DOM elements struggle

3. Cumulative Layout Shift (CLS) under 0.1

CLS measures visual stability — does stuff jump around while the page loads? Ever try to click a button and an ad loads above it, pushing the button down? That’s layout shift.

How to fix high CLS:

• Set explicit width and height on all images and videos
• Reserve space for ads and embeds before they load
• Use font-display: swap for web fonts (and preload them)
• Avoid inserting content above existing content dynamically

Crawlability and indexing (items 4-7)

If Google can’t find and understand your pages, nothing else matters.

4. XML sitemap submitted and current

Your XML sitemap tells Google every page you want indexed. It should:

• Include all important pages (not just blog posts)
• Exclude noindex pages, redirects, and parameter URLs
• Update automatically when you publish or remove content
• Be submitted in Google Search Console

Check it: visit yourdomain.com/sitemap.xml. If you see a blank page or 404, you need to fix this immediately.

5. Robots.txt configured correctly

Robots.txt tells search engines what they can and can’t crawl. Common mistakes:

• Accidentally blocking important pages or your entire site
• Blocking CSS/JS files (Google needs to render your page)
• Not referencing your sitemap in robots.txt

Your robots.txt should include:

User-agent: *
Allow: /
Sitemap: https://yourdomain.com/sitemap.xml

6. No orphan pages

An orphan page is a page with no internal links pointing to it. If Google can’t reach it by following links from other pages, it might never get indexed — even if it’s in your sitemap.

Fix: Every important page should be linked from at least 2-3 other pages on your site.

7. Clean URL structure

URLs should be readable and descriptive:

• Good: /services/roof-replacement/
• Bad: /page?id=847&cat=3&ref=homepage

Use hyphens, not underscores. Keep URLs short. Include the primary keyword when natural.

Structured data (items 8-10)

Structured data helps Google (and AI search engines) understand your content beyond just the text on the page.

8. LocalBusiness schema on homepage

If you’re a local business, this is essential. LocalBusiness schema tells Google your business name, address, phone, hours, service area, and more — in a format it can parse perfectly.

Minimum fields to include:

• Business name, address, phone (NAP)
• Opening hours
• Service area
• Price range
• Image/logo URL
• Social media links

9. Article and FAQ schema on blog posts

Every blog post should have Article schema (tells Google the author, publish date, and headline) and FAQ schema where relevant (increases your chances of appearing in AI Overviews and featured snippets by 2-3x).

10. Service/Product schema on service pages

Each service page should have schema describing what you offer, the price range, area served, and aggregate ratings if available. This data feeds directly into AI answer engines.

Validate all schema: Use Google’s Rich Results Test (search.google.com/test/rich-results) to confirm your markup is error-free.

Security and performance (items 11-13)

11. HTTPS everywhere

Every page on your site must load over HTTPS. Google confirmed HTTPS as a ranking signal back in 2014, and in 2026, browsers actively warn users about HTTP sites. Check for mixed content warnings — pages that load over HTTPS but include HTTP resources.

12. Security headers configured

Security headers protect your site and signal trustworthiness:

• Content-Security-Policy — prevents cross-site scripting attacks
• X-Frame-Options — prevents your site from being embedded in malicious iframes
• Strict-Transport-Security — forces HTTPS connections
• X-Content-Type-Options — prevents MIME type sniffing
• Referrer-Policy — controls what information is sent when users click links

These take 10 minutes to set up and improve both security and SEO trust signals.

13. Image optimization

Images are usually the heaviest elements on any page. Optimize them:

• Use WebP or AVIF format (30-50% smaller than JPEG at similar quality)
• Resize to display dimensions (don’t serve a 4000px image in a 800px container)
• Implement lazy loading for images below the fold
• Add descriptive alt text to every image (helps SEO and accessibility)
• Use a CDN for image delivery

AI search readiness (items 14-15)

14. llms.txt file

This is new for 2026 but increasingly important. An llms.txt file at your domain root tells AI crawlers what your business does, your key services, and where to find important information. Think of it as a business card for AI systems.

Include:

• Business name and one-sentence description
• Core services with links to relevant pages
• Service area
• Contact information
• Links to your most important content

15. Content formatted for AI extraction

AI answer engines extract information best when it’s clearly structured:

• Lead with the answer in the first 1-2 sentences of every page
• Use question-format H2 headings (“How much does X cost?” as a heading)
• Include definition paragraphs — “X is a process that…” formats are easy for AI to extract
• Use tables for comparisons — AI systems love structured data in tables
• Keep paragraphs short — 2-4 sentences max

How to use this checklist

Don’t try to fix everything at once. Prioritize by impact:

This week: Items 1-3 (Core Web Vitals) and items 4-5 (sitemap and robots.txt) Next week: Items 8-10 (structured data) Week 3: Items 11-13 (security and images) Week 4: Items 6-7 and 14-15 (cleanup and AI readiness)

Want to know where your site stands right now? Run a free Website Analyzer scan — it checks most of these items automatically and gives you a prioritized list of what to fix first. At WeLead Lab, we handle all 15 items as part of every client engagement, backed by our 60-day results guarantee.