Selenium was created by Jason Huggins at ThoughtWorks in 2004, making it one of the oldest browser automation tools still in active use. The project is governed by the Selenium project committee and supported by organizations like BrowserStack and Sauce Labs.
Selenium WebDriver, the core of the project, provides a programming interface to control web browsers. It supports Chrome, Firefox, Safari, Edge, and Internet Explorer through browser-specific drivers. Tests can be written in Java, Python, C#, Ruby, JavaScript, and Kotlin — more language support than any other browser testing tool.
Selenium Grid allows running tests in parallel across multiple machines and browsers. You can distribute your test suite across a fleet of machines, dramatically reducing execution time. Cloud-based Selenium grids from BrowserStack, Sauce Labs, and LambdaTest give access to hundreds of browser-OS combinations without maintaining your own infrastructure.
Selenium 4, released in 2021, brought the W3C WebDriver protocol, relative locators for finding elements based on their visual position, and improved CDP (Chrome DevTools Protocol) support. The Selenium IDE browser extension lets non-programmers record and play back browser interactions.
Despite newer alternatives like Playwright and Cypress, Selenium remains the most widely used browser testing framework globally. It’s especially dominant in enterprise environments with Java and C# codebases. The project has over 30,000 GitHub stars and a massive ecosystem of third-party tools, frameworks, and integrations built on top of it.
