Technical SEO is the foundation that every other SEO effort sits on. If Google cannot efficiently crawl, render, and index your site, no amount of content or links will rescue your rankings. This checklist covers every technical SEO factor that matters in 2025.
1. Crawlability
Google must be able to reach every page you want indexed. Start here before anything else.
- robots.txt: Confirm it is not accidentally blocking critical sections. Test at yourdomain.com/robots.txt and validate in Google Search Console.
- Crawl budget: For large sites (10,000+ pages), ensure crawl budget is not wasted on paginated URLs, duplicate parameter variations, or thin session-based pages.
- Internal links: Every important page should be reachable within 3 clicks from the homepage. Orphaned pages do not get crawled reliably.
- Redirect chains: Each redirect hop wastes crawl budget and dilutes link equity. Flatten all redirect chains to a single 301.
2. Indexation
- Coverage report: Audit Google Search Console’s Index Coverage report monthly. Pages stuck in Discovered — Not Indexed need investigation.
- Canonical tags: Every page should have a self-referencing canonical. Duplicate content pages should canonical to the master version.
- Noindex tags: Confirm that noindex is not applied to pages you want to rank. A single accidental noindex on a key template can de-index thousands of pages.
- XML sitemap: Include only indexable, canonical URLs. Submit via GSC. Exclude noindex pages, redirects, and 404s.
3. Core Web Vitals
Core Web Vitals are now a confirmed ranking signal. All three metrics need to pass in the field data (CrUX), not just lab data.
- LCP (Largest Contentful Paint): Target under 2.5 seconds. Typically the hero image or heading. Optimise with preload hints, next-gen image formats (WebP/AVIF), and a CDN.
- INP (Interaction to Next Paint): Replaced FID in March 2024. Target under 200ms. Audit JavaScript execution and long tasks in Chrome DevTools.
- CLS (Cumulative Layout Shift): Target under 0.1. Set explicit width and height attributes on all images and embeds.
4. HTTPS and Security
- HTTPS enforced sitewide with valid SSL certificate (check expiry)
- HTTP to HTTPS 301 redirect in place
- No mixed content warnings on HTTPS pages
- HSTS header configured
5. Mobile Optimisation
Google uses mobile-first indexing. Your mobile experience is your primary ranking experience.
- Test all pages in Google’s Mobile Friendly Test tool
- Ensure viewport meta tag is correctly set
- Confirm tap targets are at least 48x48px
- No horizontal scrolling on mobile devices
- Font size minimum 16px for body text
6. URL Structure
- Short, descriptive, keyword-rich URLs (max 3-4 words)
- Lowercase only, hyphens as separators (not underscores)
- No session IDs, tracking parameters, or dynamic characters in indexable URLs
- Consistent www vs non-www (enforce one and 301 the other)
7. Schema Markup
Structured data helps Google understand your content and can unlock rich results in SERPs.
- Homepage: Organization, WebSite with SearchAction
- Blog posts: Article or BlogPosting
- FAQ content: FAQPage (each Q&A pair)
- Service pages: Service or ProfessionalService
- Reviews/testimonials: AggregateRating where applicable
Validate all schema at schema.org/validator and Google’s Rich Results Test.
8. Page Speed
- Google PageSpeed score above 80 on mobile
- Images compressed (use WebP/AVIF, target under 100KB per image)
- Lazy loading on below-fold images
- CSS and JS minified and deferred where possible
- CDN configured for static assets
- Server response time (TTFB) under 800ms
9. JavaScript Rendering
If your site uses heavy JavaScript frameworks, Google’s crawler may not render your content correctly.
- Test critical pages with Googlebot’s mobile user agent in GSC’s URL Inspection tool
- Confirm that your main content is visible in the rendered HTML, not only post-JavaScript execution
- Consider server-side rendering (SSR) or static generation for content-critical pages
10. E-E-A-T Signals
Experience, Expertise, Authoritativeness, and Trustworthiness. Not a direct ranking factor but strongly correlates with ranking performance.
- Author bios with credentials on all blog posts
- About page with real team information
- Physical address and contact information visible
- Privacy policy and terms of service published
- External links to credible sources where relevant
Running This Checklist
Use this checklist alongside a dedicated crawl tool (Screaming Frog, Sitebulb, or Ahrefs Site Audit). Run a full crawl monthly on large sites, quarterly on smaller sites. Address critical issues (noindex, redirect chains, broken links) before cosmetic ones.
If you want your site audited against all 200 of our internal technical SEO checks, request your free audit.