In-depth technical SEO analysis and SEO on-page testing tool for websites optimization
Dr. Link Check - Broken link checker with malware and parked domain detection
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
BrokenLinkCheck - Free Broken Link Checker / Online Dead Link Checking Tool - find bad hyperlinks
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
LinkChecker - LinkChecker is a free, GPL licensed website validator.
SEO PowerSuite - Get all SEO tools in one pack - download free edition of SEO PowerSuite and get top 10 rankings for your site on Google and other search engines!