Webpack 5 is a powerful module packaging tool that can be used to package many scattered modules into one (or more) bundles according to their dependencies. In Webpack 5, there are mainly two development modes, namely development mode (development) and production mode (production). The main differences and respective functions of these two modes are as follows:
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Development mode (development): This mode is mainly to improve the experience in the development process, and some optimizations have been made. like:
- Hot module replacement (HMR) is enabled: Modules can be replaced, added, or removed while the application is running without a full page refresh.
- Optimized build speed: used faster in-memory compilation and evaluation.
- Provides more detailed error and warning information: to help developers better understand and solve problems.
- The compiled code will not be compressed, which is convenient for debugging and analysis.
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Production mode (production): This mode is mainly to optimize the packaged code and improve operating efficiency. like:
- Automatically delete unreferenced code (tree shaking): only pack the code that is actually needed, reducing the size of the bundle.
- Automatic code compression: use tools such as UglifyJS or Terser to delete useless characters such as spaces and newlines in the code, simplify variable names, etc., to reduce the size of the bundle.
- Automatically set process.env.NODE_ENV to production, allowing some libraries such as React to run more optimized code in the production environment.
Remember, you can choose which mode to use by setting modethe field to developmentor in the webpack configuration file . productionBy default, modethe value is production.