BACKLNK is a website and toolset for learning how websites appear in search results and AI answers. It provides free SEO and AI visibility checks along with instructional guides on search visibility, AI visibility, and related technical topics. The site is aimed at site owners, publishers, and SEO practitioners who need to assess indexability, crawler access, metadata, structured data, page structure, redirects, and HTTP headers. The free tools are powered by aSERP. The checks include an indexability checker that returns one verdict per URL with supporting evidence; a meta tags and social preview check for title, description, canonical, Open Graph, and X cards; an AI crawler access checker that reviews robots.txt and meta robots rules; a page structure and readability auditor covering heading outline, content blocks, readability, and accessibility observations; an entity signal and schema checker for JSON-LD entities such as Organization, Person, and FAQPage with sameAs links; and a redirect and HTTP header checker for redirect hops, status codes, caching, indexing, and security headers. Users can run a single check or a combined website check in one run. After confirming an email address, they receive one PDF report by email and a private online report. The checks are free and state their scope and limits, with evidence for each finding. BACKLNK also publishes guides and original research on search and AI visibility. Guide topics include AI crawler access and robots.txt configuration, getting cited in AI answers, schema markup for AI search, llms.txt, Open Graph tags and link previews, image SEO, orphan pages, search intent, and foundational crawling and indexing topics. Original research includes an evaluation of 25 crawler tokens against robots.txt answers from 5,996 reachable sites in the top 10,000 to examine which sites block AI training, AI search, and user fetchers. The site is available at https://backlnk.com.