Its biggest advantage is that it is very customizable.
Selenium HQ supports multiple programming languages, allowing integration with Java, Python, C++, and .NET. It offers open-source access with broad community support, enabling testing across various browsers. Users can automate UI tasks and customize tests, improving efficiency. However, its complexity and need for programming skills can be a barrier. Issues with dynamic elements, Internet Explorer, and lack of built-in reporting tools are notable, though it excels in scalability and parallel testing.