Free SEO Checker by Spotibo - An SEO checker that analyses based on Google's algorithm 👀
Ahrefs Backlink Checker - With the world's biggest index of live backlinks (over 15 trillion), Ahrefs Backlink Checker will show you the most complete backlink profile for any website.
SEO Analyzer By Neil Patel - A free SEO analyzer for your site
Backlinks by Neil Patel - A backlinks research tool for competitive intelligence
Curatedseotools.com - Curated directory of the best SEO tools.
SEMScoop - Find and analyze easy to rank long-tail keywords with free SEMScoop Keyword Difficulty Tool, Start using them for SEO, PPC, content creation and all your marketing activities