Key takeaways
- Technical SEO is binary. You either pass each check or you do not, and a single failure can deindex an entire site.
- The twelve checks are equally weighted but they are not equally likely to fail. The top three offenders on small sites are leftover noindex tags, broken robots.txt, and missing canonicals.
- HTTPS is non-negotiable in 2026. Let's Encrypt certificates are free and automated on most hosts.
- Mobile-first indexing means the mobile experience is the primary version Google ranks. If your site breaks on a phone, the sub-score caps at 40.
- Technical is a floor, not a ceiling. Once you clear it, stop optimising and move to content, E-E-A-T, and structure where the gains compound.
Technical SEO is the floor of the SEO + GEO AI Search Score. If it is broken, nothing else matters. You can have the best content in your niche, a perfect E-E-A-T profile, and blazing performance, but a single noindex tag on your homepage will tank your visibility to zero. The technical sub-score weighs 15% of the global number and this guide walks through the twelve binary checks Bloomwise runs, in the order you should fix them if any are failing.
The twelve technical checks
| # | Check | What it means | Fix time |
|---|---|---|---|
| 1 | HTTPS with valid cert | Secure connection, no warnings | 30 min |
| 2 | robots.txt accessible | Crawlers can fetch the file | 5 min |
| 3 | robots.txt does not block vital pages | No Disallow on root or key sections | 10 min |
| 4 | XML sitemap present | Submitted in Search Console | 15 min |
| 5 | Canonical tags on every page | Each page has one correct canonical | 1 hour |
| 6 | No noindex on live pages | Meta robots or HTTP header | 15 min |
| 7 | Mobile-friendly | Passes Google Mobile-Friendly test | Varies |
| 8 | No redirect chains | Every redirect hops once, not multiple times | 1 hour |
| 9 | 404 page exists and returns 404 | Not a soft 404 or redirect | 15 min |
| 10 | Structured data valid | Passes Rich Results Test | 30 min |
| 11 | Readable HTML | No client-side-only rendering of critical content | Varies |
| 12 | No render-blocking resources | CSS and JS do not delay first paint | 1 hour |
Run them in this order and the score climbs predictably.
Check 1: HTTPS with valid certificate
Test it: visit your homepage in Chrome. If you see a lock icon, you pass. If you see "Not secure" or a red warning, you fail.
The fix: Let's Encrypt provides free SSL certificates. Most modern hosts (Vercel, Netlify, Cloudflare Pages, managed WordPress) provision them automatically. On a VPS, run certbot --nginx and you are done in 5 minutes.
Check 2: robots.txt accessible
Visit yourdomain.com/robots.txt in your browser. If you see a plain text file, you pass. If you see 404, you fail.
The fix: create a robots.txt in your site root with at minimum:
User-agent: *
Allow: /
Sitemap: https://yourdomain.com/sitemap.xml
Check 3: robots.txt does not block vital pages
Read the file. Any Disallow: / or Disallow: /blog/ or Disallow: /products/ that blocks pages you want indexed is a critical failure.
The fix: remove the offending Disallow lines. This is a common leftover from staging environments and dev settings. Diagnose with our guide to sites not showing on Google if you are not sure what is blocked.
Check 4: XML sitemap present
Most CMSes generate a sitemap automatically. If yours does not, use a plugin or framework feature. Submit the sitemap URL in Google Search Console > Sitemaps.
What a good sitemap contains: every indexable URL, with lastmod, changefreq, and priority. Exclude tag pages, paginated archives, and utility pages that do not need to rank.
Check 5: Canonical tags on every page
View the HTML source of any page and look for <link rel="canonical" href="...">. It should point to the same page (or to the chosen master version if multiple URLs serve the same content).
Common canonical mistakes: every page canonicalising to the homepage, canonical pointing to HTTP while the site is HTTPS, www and non-www inconsistency. The content score guide covers the content-side implications, but the canonical itself is a technical fix.
Check 6: No noindex on live pages
Check the HTML source for <meta name="robots" content="noindex"> or an X-Robots-Tag HTTP header. Any page you want indexed must not have this tag.
Common causes:
- WordPress "discourage search engines" setting left on
- Plugin defaulting to noindex on new posts
- Inherited template tag not cleaned up after migration
Check 7: Mobile-friendly
Run Google's Mobile-Friendly Test or use PageSpeed Insights mobile view. A failing mobile layout is a hard ceiling on your score.
The fix: responsive design, viewport meta tag, no horizontal scroll, tap targets at least 48x48 pixels, readable font size. Most modern themes handle this by default. Older themes and custom sites built before 2015 are where problems hide.
Check 8: No redirect chains
Use a tool like Screaming Frog (free for small sites) or the Redirect Trace Chrome extension. Every redirect should go from old URL to final URL in one hop.
Example of a bad chain:
/old-url → 301 → /intermediate → 301 → /new-url
Fix: update the first redirect to point directly to the final destination.
Check 9: 404 page returns 404
A real 404 page returns HTTP status 404. A soft 404 returns 200 with "page not found" text, which confuses Google.
Check: use the Chrome DevTools Network tab. Visit a non-existent URL on your site. The response status must be 404.
Check 10: Structured data valid
Run the Rich Results Test on your homepage and a blog post. Errors in structured data mean AI engines and Google are ignoring those schemas entirely. Pair this with the structure score guide since the two overlap.
Check 11: Readable HTML
Disable JavaScript in your browser and reload your page. Can you still read the main content? If the page is blank, Google can still render your JS but AI crawlers mostly cannot. Make critical content visible in the initial HTML response.
Check 12: No render-blocking resources
Use PageSpeed Insights to identify render-blocking CSS or JS. Move non-critical CSS to rel="preload" or async loading, defer non-critical JS.
The technical recovery workflow
If your technical sub-score is under 50, run this sequence:
- Check for noindex and robots.txt Disallow (10 minutes, fix immediately)
- Verify HTTPS and certificate validity (5 minutes)
- Submit or resubmit your sitemap in Google Search Console (5 minutes)
- Audit canonical tags on your top 20 pages (30 minutes)
- Run the Mobile-Friendly Test and fix any failures (varies)
- Collapse redirect chains if present (1 hour)
- Validate structured data with Rich Results Test (20 minutes)
Most sites jump from the 40 to 60 range to 85+ in a single afternoon once the blockers are cleared. Verify with a new Google Search Console crawl after each major fix.
Technical SEO is the sub-score you fix once and forget. The twelve checks are not going to change dramatically over the next year, and once they all pass, your site is eligible to rank. Then every point of effort goes into content, E-E-A-T, and structure, where the compounding is real. Set calendar reminders to re-audit quarterly, because technical debt creeps back in during redesigns and migrations.
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