New Relic Browser is the most deployed real user monitoring (RUM) tool in the world, providing quick context for developers to solve problems in modern software stacks. It helps businesses understand their end-user experience and relationship between website performance and technology stack health. With its dominance in the RUM market, New Relic Browser is deployed on nearly 1.8 million websites, over 20 times more sites than comparable monitoring solutions. Its popularity stems from its built-in support for modern web experiences, integration with the larger New Relic platform, ease of setup, and immediate time to value. Key features include SPA handling, user-centric performance metrics, AJAX monitoring, JavaScript error monitoring, and custom attribute support. The tool integrates seamlessly with the rest of the New Relic platform, allowing users to navigate from real user monitoring to application layer to infrastructure layer easily. Browser is also easy to set up and provides immediate value, making it a critical component of successful digital business strategies.