Cypress.io - Slow, difficult and unreliable testing for anything that runs in a browser. Install Cypress in seconds and take the pain out of front-end testing.
Dr. Link Check - Broken link checker with malware and parked domain detection
RainforestQA - Insanely simple testing. Create tests for your website in plain English, then run them across all major browsers with a single click. Powered by human intelligence
LinkChecker - LinkChecker is a free, GPL licensed website validator.
Parrot QA - Automate your bug testing without writing a line of code.
SiteInspector - Catch spelling/grammar errors and broken links on websites.