SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
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!
Lumar - (Previously DeepCrawl) Hosted SEO spider to analyze and find problems with websites.
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
Website Checker Tech - WebsiteChecker.Tech is SaaS tool that detects SEO and availability issues of your website, making it easier for you to fix them.
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.