React notification libraries streamline the process of constructing and displaying alerts effectively within React-based web applications. These libraries offer various types of notifications, such as toast, snackbar, alert, and modal, each serving a unique purpose in user experience. Some popular React notification libraries include react-toastify, react-hot-toast, notistack, and react-notification-system. When choosing the right library for your project, consider factors like size, performance, customization, and accessibility features. Among these options, react-toastify stands out as a comprehensive choice due to its balance of features and ease of use.