Technical SEO checklist for 2026: 12 checks that matter

Technical SEO is the layer under your content. It decides whether search engines can reach a page, understand it and serve it fast. Google now crawls and indexes the web with its smartphone crawler, so the mobile version of each page is the version that counts. Generative search does not change the foundations: Google's guidance on AI features says a page must be indexed and eligible to show a snippet before it can appear in AI Overviews or AI Mode.

Think of technical SEO as a gate, not a lever. Content and links move rankings. Technical problems cap them.

1. robots.txt. It sits at the root of the domain and controls crawling. Make sure it does not block CSS, JavaScript or whole sections by accident. It does not control indexing: a blocked URL can still be indexed if other pages link to it.
2. noindex where you mean it. Use a robots meta tag or an X-Robots-Tag header. Google stopped supporting noindex inside robots.txt in 2019, and a page blocked by robots.txt cannot show Google its noindex tag.
3. XML sitemaps. List only canonical URLs that return 200 and are indexable. Google's limit is 50,000 URLs or 50MB uncompressed per sitemap file. Google ignores the priority and changefreq values and uses lastmod only when it is consistently accurate.
4. Canonical tags. One per page, pointing to the absolute URL of the preferred version, and consistent with your internal links and sitemap.
5. HTTPS and one host. Every variant (http, www, non-www) should redirect in one hop to a single secure version.
6. Status codes. 301 for content that has moved permanently, 404 or 410 for content that is gone, no redirect chains, and no soft 404s (error pages that return 200).
7. Mobile parity. The mobile page must carry the same main content, headings, structured data and links as the desktop page.
8. Core Web Vitals. Good means Largest Contentful Paint of 2.5 seconds or less, Interaction to Next Paint of 200 milliseconds or less and Cumulative Layout Shift of 0.1 or less, measured at the 75th percentile of real visits. See what Core Web Vitals are.
9. JavaScript rendering. Important text and links should be in the rendered HTML, and links must be real anchor elements with an href.
10. Structured data. Valid, matching the visible content and free of errors in Search Console.
11. hreflang. If you serve several languages or countries, each version references the others and itself, with return links.
12. Internal links. Every page you want indexed is linked from at least one other page, and important pages sit within a few clicks of the home page.

You can run every check above with free or inexpensive tools.

PageSpeed Insights shows two kinds of data: lab data from a simulated load, and field data from the Chrome UX Report, which reflects real visitors. Google's page experience assessment uses the field data, so treat the lab score as a diagnostic, not the verdict.

Usually not. Google's documentation says crawl budget is mainly a concern for very large sites, roughly a million or more unique pages that change weekly, or ten thousand or more that change daily. For a site with a few hundred pages, an indexing problem is almost always caused by quality, duplication or a blocking rule rather than budget.

Run a light check monthly: the Page indexing report, Core Web Vitals report and any new errors. Run the full checklist after every redesign, platform change or migration, because that is when most technical damage happens. If a rebuild is coming, plan the SEO checks into the web design project rather than after launch. If you would rather hand it over, our technical SEO audit runs this checklist and fixes what it finds.