SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
SEOmator - SEO website analysis & audit tool
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.
Ahrefs - Ahrefs is a toolset for SEO and marketing. We have tools for backlink research, organic traffic research, keyword research, content marketing & more. Give Ahrefs a try!
Majestic - Majestic - Link intelligence tools for SEO and Internet PR and Marketing. Site Explorer shows inbound link and site summary data.