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.
Netpeak Spider - A desktop tool for fast and comprehensive technical audit of the entire website.
Backlinks by Neil Patel - A backlinks research tool for competitive intelligence
Checkbot - Checkbot will boost the SEO, speed and security of your site by checking you're following 50+ web best practices. Browser extension with free and paid plans.
Toxic Backlink Checker - Find out what's lurking in your backlink profile.
SEO Crawler - A web-based crawler with real-time crawl feedback.