What Is Technical SEO? A Developer's Checklist

Content gets most of the SEO conversation, but content can only rank if search engines can crawl, render and understand your site in the first place. That layer is technical SEO — and because it lives in the build, it is either done by the developer or done by nobody.

Here is the checklist I run before any site I build goes live. It is short enough to actually use and covers the failures I find most often when auditing existing sites.

Crawlability. Every important page must be reachable by following links from somewhere crawlers already know. Orphan pages — reachable only by typing a URL — are effectively invisible. Your robots.txt must not accidentally block CSS, JavaScript or whole sections: Google needs to render your pages, and blocking styles or scripts can make the rendered version look broken.

Indexability. Each page needs a self-referencing canonical tag so duplicates (parameterized URLs, trailing slashes, www versus non-www) consolidate their ranking power. Behind login or in a staging environment? Keep those out of the index deliberately. And keep a clean XML sitemap at /sitemap.xml, referenced from robots.txt, listing exactly the pages you want ranked — plus hreflang entries if you serve multiple languages.

Speed and stability. Core Web Vitals are a ranking signal, and they are earned in the build: compressed images with explicit dimensions, minimal and deferred JavaScript, long-lived caching, and a CDN. This is the overlap of SEO and good engineering, and it is where developer-built sites beat plugin-stuffed templates every time.

Mobile. Google indexes the mobile version first, so the phone experience is not the compromise — it is the product. Test on real devices.

Clean URLs and status codes. Descriptive, stable, lowercase, hyphenated URLs — /pricing not /page?id=274. Redirects return 301s, not chains of four hops. Missing pages return a proper 404, not a soft 200 with an empty layout. And nothing on the site should link to a dead URL; crawl your own site monthly and fix what 404s.

Structured data. JSON-LD describing your organization, articles, products or FAQs gives search engines confident answers and can earn rich results. It costs an hour and compounds for years — there is no reason to skip it.

Security and protocol. HTTPS everywhere, with all HTTP traffic redirected. It is a confirmed ranking signal, and browsers now label plain HTTP as unsafe, which kills trust faster than any ranking.

Finally, the meta layer that people overestimate and underdo at once: one unique, keyword-natural title per page, one meta description written as an ad for the click, meaningful heading hierarchy with exactly one h1, descriptive alt text, and internal links that use honest words instead of "click here."

None of this is glamorous, which is exactly why it differentiates: most sites leak ranking power through a dozen small technical holes. Fix the holes, and the content you already have starts working harder. A technical pass is part of every site I launch — and it is the first thing I check when a good site refuses to rank.