DareBoost - DareBoost is an online tool to test, analyze and monitor your website: speed, SEO, quality, security. All you need for website optimization in a single service.
Dead Link Checker - Check for broken links on any website
Lighthouse - Collaborate effortlessly on projects. Whether you’re a team of 5 or studio of 50, Lighthouse will help you keep track of your project development with ease.
BrokenLinkCheck - Free Broken Link Checker / Online Dead Link Checking Tool - find bad hyperlinks
Passmarked - Simple, all-in-one test to check the quality of your website
LinkChecker - LinkChecker is a free, GPL licensed website validator.