Web application performance affects the retention rate of users. If a page load time is too long, the user will give up. So we need to monitor the web application to understand performance and ensure that servers are stable, available and healthy. Apache SkyWalking is an application performance monitoring (APM) tool designed especially for cloud native and container-based architectures. Its skywalking-client-js is a lightweight, client-side JavaScript exception, performance and tracing library.