The Technical SEO Checklist
Technical issues quietly cap your rankings. This checklist covers HTTPS, redirects, status codes, broken links and headers — and how to check each one free.
Why technical SEO quietly matters
You can publish perfect content and still underperform because of a chain of small technical faults: an expiring certificate, a redirect loop, a wave of 404s, a slow server. This checklist finds and fixes them.
1. HTTPS and SSL
- Valid, non-expired certificate covering the right hostnames.
- No mixed content (insecure images or scripts on a secure page).
- HTTP redirects permanently (301) to HTTPS.
Check with the SSL checker.
2. Redirects
- Every old URL 301s to its closest new equivalent.
- No chains: A → B → C should be A → C.
- No loops.
- Update internal links to point at the final URL.
Audit with the redirect checker.
3. HTTP status codes
Expected codes: 200 for pages, 301/302 for redirects, 404 for genuinely missing pages, 410 for permanently removed. Anything returning 5xx is a crawling problem.
Scan with the HTTP status checker.
4. Broken links
- Fix or remove internal 404s.
- Reclaim lost inbound links by restoring or redirecting the target page.
- Keep the sitemap free of error URLs.
Find them with the broken link checker.
5. DNS and hosting
- Fast, reliable DNS resolution.
- Correct A / AAAA / CNAME records.
- No downtime spikes that make crawlers back off.
Check with the DNS checker.
6. Headers and canonicalisation
- One canonical hostname (www vs non-www; trailing slash).
- Correct
Content-Typeandcharset. X-Robots-Tagnot accidentally set tonoindex.- Caching and compression enabled.
Inspect with the HTTP header checker.
7. The fundamentals
- Mobile-friendly and responsive.
- Fast — good Core Web Vitals (LCP, INP, CLS).
- Indexable — no stray
noindex, robots.txt or canonical errors. - Structured data validated.
- Sitemap submitted and error-free.
How often to check
Run the full checklist after every deploy, migration or redesign — and spot-check monthly. Automation beats memory.
Run the checks free
Every tool on this list is free, unlimited and runs in your browser. Start with the SSL checker and work down the list.