Selenium

Selenium is an open-source suite of tools with four key components: Selenium IDE (browser extension for record-and-playback), Selenium Grid (parallel test execution), Selenium WebDriver (language-specific bindings to drive a browser), and Selenium RC (legacy component). It supports Java, Python, C#, JavaScript, and Ruby across Chrome, Firefox, Edge, and Safari. Selenium can integrate with multiple testing frameworks like JUnit, TestNG, and NUnit. Selenium works by simulating real user interactions in the browser by logging in, clicking menus, submitting forms, and navigating workflows, interacting directly with the DOM to validate front-end behavior. It is a free and open-source solution making it cost-effective and eliminates repetitive manual testing.