Technical SEO Checklist: 20 Fixes That Actually Move Rankings in 2026

Crawlability & Indexation (Critical)

1. robots.txt blocking important pages — Check robots.txt is not accidentally blocking CSS, JS, or key page directories. Use Google Search Console's robots.txt tester.

2. Noindex tags on live pages — Developers sometimes leave noindex on pages after staging. Audit all pages with in Search Console.

3. Crawl errors — 404s on internally-linked pages waste crawl budget and confuse users. Fix or redirect all crawl errors in GSC.

4. Redirect chains — A→B→C→D chains slow crawling and dilute link equity. Flatten all redirects to single hops (A→D).

5. Duplicate content without canonicals — Faceted navigation, URL parameters, and pagination often create duplicate pages. Implement canonical tags on all variations.

Core Web Vitals & Page Speed (High Impact)

6. LCP above 2.5 seconds — Largest Contentful Paint measures how fast your main content loads. Common causes: unoptimised hero images, render-blocking fonts, slow server response. Fix: compress images to WebP, use preload for above-fold images.

7. CLS above 0.1 — Cumulative Layout Shift measures visual stability. Common cause: images without defined dimensions, web fonts loading late. Fix: always specify width and height on images.

8. INP above 200ms — Interaction to Next Paint (replaced FID in March 2024). Measures responsiveness to user interactions. Fix: reduce JavaScript execution time, defer non-critical scripts.

9. TTFB above 600ms — Time To First Byte. A slow server response kills everything downstream. Fix: upgrade hosting, add a CDN, implement server-side caching.

On-Page Structure (Medium-High Impact)

10. Missing or duplicate title tags — Every page needs a unique, keyword-containing title under 60 characters. Duplicate titles are a crawl waste and missed ranking opportunity.

11. Missing or duplicate meta descriptions — Not a direct ranking factor, but affects CTR. Each page should have a unique, compelling 150–160 character description.

12. Multiple H1 tags — One H1 per page, containing the primary keyword. H1s should align with title tags.

13. Broken internal links — Every 404 on an internal link wastes PageRank. Crawl your site monthly and fix broken links immediately.

14. Missing alt text on images — Alt text is an indexation signal and accessibility requirement. Every meaningful image needs descriptive alt text.

Schema & Structured Data (Medium Impact)

15. Missing LocalBusiness schema — For any business with a physical location, JSON-LD LocalBusiness schema signals your NAP, hours, and location to Google. Missing this delays Google's entity understanding of your business.

16. Missing FAQPage schema — FAQ schemas can generate rich results in SERPs, dramatically increasing click-through rate. Implement on service pages and blog posts with Q&A sections.

17. Duplicate FAQPage schemas — Multiple FAQPage schemas on the same URL (e.g. from a plugin + manual implementation) confuse Google and cause rich results to be ignored.

Mobile & HTTPS (Critical)

18. Non-mobile-responsive pages — Google uses mobile-first indexing. Any page that does not render correctly on mobile is at a significant ranking disadvantage. Test all pages with Google's Mobile-Friendly Test.

19. Mixed content (HTTP on HTTPS site) — Loading HTTP resources on an HTTPS page triggers browser warnings and signals poor maintenance. Fix all mixed content warnings in Chrome DevTools.

20. Missing or incorrect canonical tags — Self-referencing canonicals on all indexable pages, cross-domain canonicals on syndicated content, and canonical consistency with hreflang (for multilingual sites) are all required for clean crawling.

How to Prioritise These Fixes

Run them in this order:

1. Fix crawlability blockers first (items 1–5) — no point optimising pages Google cannot crawl
2. Address Core Web Vitals (items 6–9) — direct ranking factor since 2021
3. Clean up on-page structure (items 10–14) — quick wins, immediate CTR and ranking impact
4. Implement structured data (items 15–17) — increases SERP real estate
5. Confirm mobile and HTTPS (items 18–20) — foundational requirements

A proper technical audit takes 2–4 days for a mid-size site (50–200 pages). Most agencies include it as a month-1 deliverable.

How to Run a Technical SEO Audit Yourself

You do not need a £5,000 audit to catch most technical issues. Here is a DIY approach that covers the critical bases:

Step 1: Google Search Console (free, 30 minutes)

Check Coverage report for: "Excluded" URLs (especially "Noindex" and "Crawled — currently not indexed"), Core Web Vitals report by URL group, and Manual Actions (penalties). If you find manual actions, fix these before anything else.

Step 2: Screaming Frog crawl (free up to 500 URLs, 1–2 hours)

Crawl your site and export: all 4xx/5xx response codes, pages with missing or duplicate title tags, pages with missing or duplicate meta descriptions, pages with multiple H1s, and pages with broken internal links. Export each as a CSV and prioritise by traffic impact.

Step 3: PageSpeed Insights (free, 2 hours)

Test your homepage, top 5 landing pages, and any pages receiving the most organic traffic. PageSpeed Insights shows field data (real user experience) which is what Google actually uses for rankings.

Step 4: Schema validation (free, 30 minutes)

Use Google's Rich Results Test on your homepage, key service pages, and blog posts. Confirm Article, FAQPage, LocalBusiness, and BreadcrumbList schemas validate without errors.

Step 5: Mobile test (free, 20 minutes)

Google Mobile-Friendly Test on your 5 most important pages. Look for: text too small, clickable elements too close, viewport not set, content wider than screen.

Technical SEO Tools for UK Businesses

The tools you actually need depend on your site size and budget:

Free tools (sufficient for most small businesses):

• Google Search Console — Indexation, Core Web Vitals, manual actions, search performance
• Bing Webmaster Tools — Same as GSC but for Bing (often overlooked — Bing drives 6–9% of UK searches)
• Google PageSpeed Insights — Field + lab data on CWV metrics
• Screaming Frog SEO Spider (free tier, 500 URLs) — Crawl analysis
• Google Rich Results Test — Schema validation
• Chrome DevTools — Network panel, Lighthouse audit, console error checking

Paid tools (for growth-stage businesses and agencies):

• Screaming Frog (£199/year) — Full crawl unlimited, JavaScript rendering, custom extraction
• Ahrefs (£89–£449/month) — Site audit, backlink analysis, keyword tracking, content gap
• Semrush (£99–£449/month) — Comprehensive suite including PPC competitor research
• Sitebulb (£13–£45/month) — Visual crawl analysis, excellent for presenting technical issues to clients
• Botify (enterprise) — JavaScript rendering at scale, crawl log analysis, for 100k+ URL sites

The UK agency standard stack: Search Console + Screaming Frog (paid) + Ahrefs + PageSpeed Insights covers 95% of what any site needs.

Technical SEO Priority Matrix: Where to Start

Not all technical issues are equal. This matrix helps you decide where to spend limited time and budget:

Fix immediately (high impact, quick to fix):

• Pages accidentally set to noindex in production
• 4xx errors on internally-linked pages (especially from homepage or top navigation)
• Mixed content warnings (HTTPS pages loading HTTP resources)
• Duplicate title tags on high-traffic templates
• Missing canonical tags on paginated content

Fix this sprint (high impact, requires development):

• LCP above 4 seconds on mobile
• CLS caused by missing image dimensions
• Redirect chains of 3+ hops
• JavaScript-blocked crawling of key content
• LocalBusiness schema missing or incorrect

Schedule for next quarter (medium impact):

• INP optimisation (JavaScript bundle splitting, third-party script auditing)
• Internal link architecture review
• Structured data expansion (FAQPage, Article, BreadcrumbList)
• XML sitemap accuracy audit
• Orphan page identification and internal linking

Monitor but deprioritise (low impact or hard to move):

• Minor CLS from web fonts (if score is <0.1, defer)
• Thin content on low-traffic pages (prune or redirect rather than rewrite)
• Keyword cannibalisation on very similar but low-traffic URLs

Spend your first 80% of effort on the top two rows. They deliver the greatest ranking impact per hour invested.