LinkChecker - LinkChecker is a free, GPL licensed website validator.
SiteCheckerTool.com - Website Analytics & Tools
DRKSpiderJava - DRKSpider is an open source website crawler (sitemap generator) and link checker. Features:
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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.
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