In general, look for dependencies. Any popular enough bundlers should have a feature or plugin to show the bundle statistics (e.g. webpack-bundle-analyzer or ro

In general, look for dependencies. Any popular enough bundlers should have a feature or plugin to show the bundle statistics (e.g. webpack-bundle-analyzer or rollup-plugin-analyzer). Audit your dependency to see if that's not requested nor needed, and try to remove them with a finer-grained dependency or leaner library or rewriting, in the order of preference. That alone is enough for usual JS apps, because not much people do so...