Getting indexed on Bing (and the engines that use it); its site scanner is a useful free technical audit.
free Open ↗Get found in search
Index, measure and speed up a site; the official consoles and the testing tools.6 listed◆ Official sources
Bing Webmaster Tools◆bing.com
Google Search Console◆search.google.com
Verifying a domain, submitting a sitemap, requesting indexing, and reading Core Web Vitals and query data. The first tool to set up on any launch.
free Open ↗
PageSpeed Insights◆pagespeed.web.dev
Finding the largest-contentful-paint element and layout shifts before launch; the field data is what Google actually uses.
free Open ↗
Rich Results Test◆search.google.com
Checking Article, HowTo, FAQ, Breadcrumb and Product JSON-LD before you rely on it.
free Open ↗Tools and services
Ahrefs Webmaster Toolsahrefs.com
A crawl-based technical audit and a backlink profile without the paid subscription; verify ownership first.
free tier Open ↗
Screaming Frog SEO Spiderscreamingfrog.co.uk
Crawling your own site before launch; free up to 500 URLs.
free tier Open ↗