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.
Backlink Tool - A backlink tool to index your links quickly and freely.
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
RobinGupta Bulk Domain Authority Checker - Free tool to bulk check domain authority, Page Authority, Spam score & IP Address.
SmallSEOTools - Do you need effective SEO tools which are 100% free? Check out our SmallSEOtools.com for checking and removing plagiarism, backlinks, tracking keyword positions, and more.
Whatsmyserp - Powerful Rank & Serp Tracking. Completely Free.