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