The 2027 Technical SEO Checklist

Technical SEO in 2027 is not about a longer checklist, it is about a stricter one. Speed, structure and machine-readability are non-negotiable for both Google and AI engines.

Rendering and delivery

Server-render or statically generate every indexable page. Client-rendered content is still parsed by Google but is unreliable for smaller AI crawlers.

Deliver from an edge network with brotli compression and HTTP/3.

Core Web Vitals thresholds

Google now weights Interaction to Next Paint heavily. The 2027 pass thresholds are LCP under 2.5 s, INP under 200 ms and CLS under 0.1 at the 75th percentile.

Structured data coverage

Ship structured data as a baseline, not an enhancement.

Organization or LocalBusiness on the home page
Article and BreadcrumbList on every editorial page
Product and Offer on every commercial page
FAQPage where genuine Q and A exists

AI crawler access

Allow GPTBot, PerplexityBot, ClaudeBot, Google-Extended and OAI-SearchBot in robots.txt. Publish an llms.txt with a canonical map of your site so retrieval systems can navigate quickly.

Indexing hygiene

Every indexable URL should have a self-referencing canonical, a valid entry in sitemap.xml, and a stable status code. Kill soft 404s and orphan pages every quarter.

FAQs

Is JavaScript SEO still risky in 2027?

For Google, JavaScript is rendered reliably. For AI crawlers, many do not execute JavaScript, so server-rendered HTML is safer.

Do I need an llms.txt file?

It is not required but recommended. It gives AI crawlers a curated map of your most important pages.

What is the single highest-impact technical fix?

Cut INP. It is the metric most sites fail on and it directly affects both rankings and user engagement.