Technical SEO checklist before launching a website

Before launching a website, check technical SEO in five areas: search engines can crawl the site, understand which pages to index, see content without JavaScript, get fast pages and read correct metadata. Most launch mistakes — a forgotten staging noindex, missing redirects from old URLs, empty HTML — take a day to fix if caught in advance.

Below is the checklist we run before every website release.

Why check technical SEO before launch?

Check technical SEO before launch because in a site's first weeks search engines form their view of it, and mistakes at that stage cost traffic that takes a long time to recover. This matters most for migrations: if old URLs are not redirected, the site loses the rankings it built up.

What most often breaks at launch:

• a robots.txt or noindex tag from staging makes it to production;
• old URLs return 404 instead of a permanent redirect to new ones;
• pages render only in the browser, so crawlers see an empty template;
• every page has the same title and description;
• the sitemap is missing or lists URLs that do not exist.

How do you check that the site can be crawled and indexed?

Check crawlability through robots.txt, the sitemap, status codes and indexing meta tags: crawlers must reach the pages you want freely and get a clear signal about which ones to index.

A minimal production robots.txt:

User-agent: *
Disallow: /admin/
Disallow: /account/
Disallow: /cart

Sitemap: https://example.com/sitemap.xml

What to check:

1. robots.txt does not block the whole site and points to the sitemap.
2. The sitemap lists only canonical pages returning 200, each with a last-modified date.
3. Missing pages return 404, not 200 with "not found" text.
4. Old URLs 301-redirect to new ones, with no chains.
5. Every page has a canonical, and a multilingual site has hreflang for every version.
6. Production has no noindex; staging does, plus password protection.

How do you check that crawlers see the content?

Checking that crawlers see the content is simple: view the page source or fetch it with curl and make sure the main text, headings and links are in the server response. If text appears only after JavaScript runs, some search engines and AI bots will see an empty page.

The fix is server-side rendering or static generation. We compared the frameworks that provide it in Nuxt vs Next.js.

Also check that:

• links in menus, pagination and cards are real <a href> elements, not buttons with click handlers;
• images have alt text;
• each page has one H1 and an H2–H3 structure that reflects the content.

Photo: Unsplash

Which metadata and markup need to be filled in?

Every page needs a unique title and description, Open Graph tags for social networks and messengers, and schema.org structured data where it fits: organisation, articles, products, FAQs.

Element	What to check	Common mistake
title	Unique, up to 60 characters, key phrase first	Same on every page
description	Unique, up to 160 characters, answers the query	Empty or copied from the body
Open Graph	Title, description, 1200×630 image	No image, so link previews are blank
canonical	Absolute URL of the primary version	Points to the home page from every page
hreflang	All language versions reference each other	Points to a version that does not exist
Structured data	Passes the validator	Markup does not match visible text

An example of blog post markup in JSON-LD:

{
  "@context": "https://schema.org",
  "@type": "BlogPosting",
  "headline": "Technical SEO checklist before launching a website",
  "datePublished": "2026-11-11T10:00:00+00:00",
  "author": { "@type": "Organization", "name": "Nordex" }
}

What should you check for speed and mobile?

For speed, check Core Web Vitals on key page templates — home, category, product, article; for mobile, check that all content and navigation work on a narrow screen. Search engines index sites primarily by their mobile version.

Quick pre-launch checks:

• images in modern formats at the right size, lazy-loaded below the fold;
• fonts do not block text rendering;
• no unnecessary JavaScript shipped to the browser;
• compression and caching of static files enabled, with a CDN;
• no horizontal scrolling or tiny tap targets on mobile.

Tools for checking

Lighthouse and PageSpeed Insights show lab and field speed data. Connect Google Search Console and Bing Webmaster Tools before launch: they show indexing errors, mobile issues and real-user speed reports.

What should you do in the first weeks after launch?

In the first weeks after launch, submit the sitemap in the webmaster tools, watch indexing error reports and confirm that traffic from old URLs reaches the new ones. Problems caught in week one are fixed without noticeable losses.

A plan for the first weeks:

1. Submit the sitemap in Google Search Console and Bing Webmaster Tools.
2. Review crawl error and excluded page reports.
3. Compare traffic to key pages with the period before migration.
4. Pull 404s from server logs and add missing redirects.
5. Check how pages look in search results and messenger previews.

In short

• Check robots.txt, the sitemap, status codes, redirects, canonical and hreflang before launch.
• Main text and links must be in the server's HTML, not appear after JavaScript.
• Every page needs a unique title and description, Open Graph and fitting schema.org markup.
• Check Core Web Vitals and the mobile version on key templates.
• Connect webmaster tools in advance and watch for errors in the first weeks.