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.
Backlinks by Neil Patel - A backlinks research tool for competitive intelligence
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
Monitor Backlinks - Easy Link Management - SEO Tool for automatically checking your backlinks.
SEOReviewTools Backlinks Checker - Use the Free Backlink Checker to uncover ➽ Total Backlinks ➽ Linking Domains ➽ Discover: ① Who is linking to you ② Find new link building opportunities