Selenium, a widely used open-source test automation framework, faces several challenges despite its popularity in automating user actions on web applications across various browsers. These challenges include handling flaky tests that result in false positives or negatives, managing dynamic content that relies on JavaScript and AJAX, and dealing with pop-up windows and multi-tab testing. The framework's scalability is limited, as it traditionally supports only sequential testing, but tools like Selenium Grid and cloud solutions like LambdaTest offer parallel testing to enhance efficiency. Mobile testing remains a hurdle for Selenium, as it primarily supports non-mobile devices, though integration with Appium can address this. Another limitation is the inability to automate everything, as some scenarios still require manual testing. Additionally, generating comprehensive test reports can be complex, but LambdaTest offers APIs to extract detailed test data and insights. While Selenium cannot test local Windows applications or bypass CAPTCHA security, it remains a valuable tool for web application testing, especially when combined with scalable cloud-based platforms.