The Angular Ahead-of-Time (AOT) compiler converts your Angular HTML and TypeScript code into efficient JavaScript code during the build phase before the browser downloads and runs that code. Compiling your application during the build process provides a faster rendering in the browser. Angular offers two ways to compile your application: Just-in-Time (JIT), which compiles your app in the browser at runtime. Ahead-of-Time (AOT), which compiles your app at build time. JIT compilation is the default when you run the ng build (build only) or ng serve (build and serve locally) CLI commands: For AOT compilation, include the --aot option with the ng build or ng serve command: ng build –aot ng serve --aot