Different Distribution files 
In the dist/ directory of the npm package you will find many different builds of Vue I18n. Here is an overview of which dist file should be used depending on the use-case.
From CDN or without a Bundler 
vue-i18n(.runtime).global(.prod).js:- For direct use via 
<script src="...">in the browser. Exposes theVueI18nglobal - In-browser message format compilation: 
vue-i18n.global.jsis the "full" build that includes both the compiler and the runtime so it supports compiling message formats on the flyvue-i18n.runtime.global.jscontains only the runtime and requires message formats to be pre-compiled during a build step
 - Inlines all Vue I18n core internal packages - i.e. it’s a single file with no dependencies on other files. This means you must import everything from this file and this file only to ensure you are getting the same instance of code
 - Contains hard-coded prod/dev branches, and the prod build is pre-minified. Use the 
*.prod.jsfiles for production 
- For direct use via 
 
NOTE
Global builds are not UMD builds. They are built as IIFEs and are only meant for direct use via <script src="...">.
vue-i18n(.runtime).esm-browser(.prod).js:- For usage via native ES modules imports (in browser via 
<script type="module">) - Shares the same runtime compilation, dependency inlining and hard-coded prod/dev behavior with the global build
 
- For usage via native ES modules imports (in browser via 
 
With a Bundler 
vue-i18n(.runtime).esm-bundler.js:- For use with bundlers like 
webpack,rollupandparcel - Leaves prod/dev branches with 
process.env.NODE_ENVguards (must be replaced by bundler) - Does not ship minified builds (to be done together with the rest of the code after bundling)
 - Imports dependencies (e.g. 
@intlify/core-base,@intlify/message-compiler)- Imported dependencies are also 
esm-bundlerbuilds and will in turn import their dependencies (e.g.@intlify/message-compilerimports@intlify/shared) - This means you can install/import these deps individually without ending up with different instances of these dependencies, but you must make sure they all resolve to the same version
 
 - Imported dependencies are also 
 - In-browser locale messages compilation: 
vue-i18n.runtime.esm-bundler.jsis runtime only, and requires all locale messages to be pre-compiled. This is the default entry for bundlers (viamodulefield inpackage.json) because when using a bundler templates are typically pre-compiled (e.g. in*.jsonfiles)vue-i18n.esm-bundler.js(default): includes the runtime compiler. Use this if you are using a bundler but still want locale messages compilation (e.g. templates via inline JavaScript strings). To use this build, change your import statement to:import { createI18n } from "vue-i18n/dist/vue-i18n.esm-bundler.js";
 
- For use with bundlers like 
 
NOTE
If you use vue-i18n.runtime.esm-bundler.js, you will need to precompile all locale messages, and you can do that with .json (.json5) or .yaml, i18n custom blocks to manage i18n resources. Therefore, you can be going to pre-compile all locale messages with bundler and the following loader / plugin.
For Node.js (Server-Side) 
vue-i18n.cjs(.prod).js:- For CommonJS usage in Node.js
 - For use in Node.js via 
require() - If you bundle your app with webpack with 
target: 'node'and properly externalizevue-i18n, this is the build that will be loaded - The dev/prod files are pre-built, but the appropriate file is automatically required based on 
process.env.NODE_ENV 
Support Version
🆕 9.3+
vue-i18n(.runtime).node.mjs:- For ES Modules usage in Node.js
 - For use in Node.js via 
import - The dev/prod files are pre-built, but the appropriate file is automatically required based on 
process.env.NODE_ENV - This module is proxy module of 
vue-i18n(.runtime).mjsvue-i18n.runtime.node.mjs: is runtime only.vue-i18n.node.mjs: includes the runtime compiler.
 
NOTE
ES Modules will be the future of the Node.js module system. The vue-i18n.cjs(.prod).js will be deprecated in the future. We recommend you would use vue-i18n(.runtime).node.mjs.