NODE_OPTIONS='-r esm' next
NODE_OPTIONS='--inspect' next
Good to know: Running next without a command is the same as running next dev
Build
next build creates an optimized production build of your application. The output displays information about each route.
Size – The number of assets downloaded when navigating to the page client-side. The size for each route only includes its dependencies.
First Load JS – The number of assets downloaded when visiting the page from the server. The amount of JS shared by all is shown as a separate metric.
Both of these values are compressed with gzip. The first load is indicated by green, yellow, or red. Aim for green for performant applications.
You can enable production profiling for React with the --profile flag in next build. This requires Next.js 9.5:
Terminal next build --profile
After that, you can use the profiler in the same way as you would in development.