Headless browsers are specialized tools that function without a graphical user interface, allowing them to perform tasks such as data collection, testing automation, performance tracking, and layout review efficiently by operating in the backend. These browsers, favored by software test engineers for their ability to streamline processes by bypassing the need to load visual elements, can execute tasks like running JavaScript and handling complex request chains without user interface considerations. However, while they offer advantages such as faster data extraction and reduced testing time, they also present challenges like increased difficulty in debugging and limitations to backend tasks only. Popular headless browsers include Google Puppeteer, PhantomJS, HtmlUnit, and Splinter, each offering unique features for specific programming environments. The use of headless browsers is enhanced when integrated with robust data collection infrastructure to simulate real-user interactions and avoid site blocks.