Screaming Frog SEO Spider - The Screaming Frog SEO Spider is a small desktop program (PC or Mac) which crawls websites’ links...
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
Free SEO Checker by Spotibo - An SEO checker that analyses based on Google's algorithm 👀
WebsiteChecker - Sends you alerts when your website goes down.
Pulno - SEO Audit and Website Analysis. Pull up your SEO.
Xenu's Link Sleuth - Xenus Link Sleuth checks Web sites for broken links.