diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index a1a0aafa5..c6feedd06 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -103,11 +103,6 @@ By default, each package will be built in multiple distribution formats as speci
     - This means you **must** import everything from this file and this file only to ensure you are getting the same instance of code.
   - Hard-coded prod/dev branches, and the prod build is pre-minified (you will have to use different paths/aliases for dev/prod)
 
-- **`cjs`**
-
-  - For use in Node.js server-side rendering via `require()`.
-  - The dev/prod files are pre-built, but are dynamically required based on `process.env.NODE_ENV` in `index.js`, which is the default entry when you do `require('vue-i18n')`.
-
 For example, to build `compiler` with the global build only:
 
 ```bash
@@ -117,7 +112,7 @@ pnpm build -- message-compiler -f global
 Multiple formats can be specified as a comma-separated list:
 
 ```bash
-pnpm build -- message-compiler -f esm-browser,cjs
+pnpm build -- message-compiler -f esm-browser,global
 ```
 
 #### Build with Source Maps
diff --git a/docs/guide/extra/dist.md b/docs/guide/extra/dist.md
index 1b8376078..be30b95ee 100644
--- a/docs/guide/extra/dist.md
+++ b/docs/guide/extra/dist.md
@@ -40,24 +40,10 @@ If you use `vue-i18n.runtime.esm-bundler.js`, you will need to precompile all lo
 
 ## 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 externalize `vue-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`<wbr/>`.NODE_ENV`
-
-:::tip Support Version
-:new: 9.3+
-:::
-
-- **`vue-i18n(.runtime).node.mjs`**:
+- **`vue-i18n(.runtime).node.js`**:
   - 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`<wbr/>`.NODE_ENV`
-  - This module is proxy module of `vue-i18n(.runtime).mjs`
-    - **`vue-i18n.runtime.node.mjs`**: is runtime only.
-    - **`vue-i18n.node.mjs`**: includes the runtime compiler.
-
-:::tip 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`.
-:::
+  - This module is proxy module of `vue-i18n(.runtime).js`
+    - **`vue-i18n.runtime.node.js`**: is runtime only.
+    - **`vue-i18n.node.js`**: includes the runtime compiler.
diff --git a/eslint.config.mjs b/eslint.config.mjs
index add504a49..66f6631d4 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -51,7 +51,7 @@ export default [
     }
   },
   {
-    files: ['**/*.js', '**/*.cjs', '**/*.mjs'],
+    files: ['**/*.js', '**/*.mjs'],
     ...ts.configs.disableTypeChecked
   },
 
@@ -95,7 +95,6 @@ export default [
       'shim.d.ts',
       'temp/**',
       '.eslintcache',
-      '.eslintrc.cjs',
       'packages/*/vite.config.ts',
       'packages/*/index.js',
       'packages/vue-i18n-core/petite.js',
diff --git a/packages/core-base/index.js b/packages/core-base/index.js
deleted file mode 100644
index 9a6a8be0a..000000000
--- a/packages/core-base/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/core-base.prod.cjs')
-} else {
-  module.exports = require('./dist/core-base.cjs')
-}
diff --git a/packages/core-base/package.json b/packages/core-base/package.json
index 1bfc37639..a38568f6b 100644
--- a/packages/core-base/package.json
+++ b/packages/core-base/package.json
@@ -24,11 +24,9 @@
     "url": "https://github.com/intlify/vue-i18n/issues"
   },
   "files": [
-    "index.js",
     "dist"
   ],
-  "main": "index.js",
-  "module": "dist/core-base.mjs",
+  "module": "dist/core-base.js",
   "unpkg": "dist/core-base.global.js",
   "jsdelivr": "dist/core-base.global.js",
   "types": "dist/core-base.d.ts",
@@ -47,25 +45,19 @@
     "formats": [
       "mjs",
       "browser",
-      "cjs",
       "global"
     ]
   },
   "exports": {
     ".": {
       "types": "./dist/core-base.d.ts",
-      "import": "./dist/core-base.mjs",
+      "import": "./dist/core-base.js",
       "browser": "./dist/core-base.esm-browser.js",
       "node": {
         "import": {
-          "production": "./dist/core-base.prod.cjs",
-          "development": "./dist/core-base.mjs",
-          "default": "./dist/core-base.mjs"
-        },
-        "require": {
-          "production": "./dist/core-base.prod.cjs",
-          "development": "./dist/core-base.cjs",
-          "default": "./index.js"
+          "production": "./dist/core-base.prod.js",
+          "development": "./dist/core-base.js",
+          "default": "./dist/core-base.js"
         }
       }
     },
diff --git a/packages/core/README.md b/packages/core/README.md
index cbaff2059..70975b72b 100644
--- a/packages/core/README.md
+++ b/packages/core/README.md
@@ -36,22 +36,13 @@ The intlify core module for i18n
 
 ### For Node.js (Server-Side)
 
-- **`core.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 externalize `@intlify/core`, 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`
-
-- **`core(.runtime).node.mjs`**:
-  - For ES Moudles usage in Node.js
+- **`core(.runtime).node.js`**:
+  - 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 `core(.runtime).mjs`
-    - **`core.runtime.node.mjs`**: is runtime only. proxy `core.runtime.mjs`
-    - **`core.node.mjs`**: includes the runtime compiler. proxy `core.mjs`
-
-> NOTE: ES Modules will be the future of the Node.js module system. The `core.cjs(.prod).js` will be deprecated in the future. We recommend you would use `core(.runtime).node.mjs`. 9.3+
-
+  - This module is proxy module of `core(.runtime).js`
+    - **`core.runtime.node.js`**: is runtime only. proxy `core.runtime.js`
+    - **`core.node.js`**: includes the runtime compiler. proxy `core.js`
 
 ## :copyright: License
 
diff --git a/packages/core/index.js b/packages/core/index.js
deleted file mode 100644
index e4e67ff60..000000000
--- a/packages/core/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/core.prod.cjs')
-} else {
-  module.exports = require('./dist/core.cjs')
-}
diff --git a/packages/core/package.json b/packages/core/package.json
index e95d19732..cf03d284a 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -24,11 +24,9 @@
     "url": "https://github.com/intlify/vue-i18n/issues"
   },
   "files": [
-    "index.js",
     "dist"
   ],
-  "main": "index.js",
-  "module": "dist/core.mjs",
+  "module": "dist/core.js",
   "unpkg": "dist/core.global.js",
   "jsdelivr": "dist/core.global.js",
   "types": "dist/core.d.ts",
@@ -48,7 +46,6 @@
       "mjs-node-runtime",
       "browser",
       "browser-runtime",
-      "cjs",
       "global",
       "global-runtime"
     ]
@@ -56,18 +53,13 @@
   "exports": {
     ".": {
       "types": "./dist/core.d.ts",
-      "import": "./dist/core.mjs",
+      "import": "./dist/core.js",
       "browser": "./dist/core.esm-browser.js",
       "node": {
         "import": {
-          "production": "./dist/core.prod.node.mjs",
-          "development": "./dist/core.node.mjs",
-          "default": "./dist/core.node.mjs"
-        },
-        "require": {
-          "production": "./dist/core.prod.cjs",
-          "development": "./dist/core.cjs",
-          "default": "./index.js"
+          "production": "./dist/core.prod.node.js",
+          "development": "./dist/core.node.js",
+          "default": "./dist/core.node.js"
         }
       }
     },
diff --git a/packages/devtools-types/index.js b/packages/devtools-types/index.js
deleted file mode 100644
index d64c0e375..000000000
--- a/packages/devtools-types/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/devtools-types.prod.cjs')
-} else {
-  module.exports = require('./dist/devtools-types.cjs')
-}
diff --git a/packages/devtools-types/package.json b/packages/devtools-types/package.json
index fd9821ae9..dc4f6dcc3 100644
--- a/packages/devtools-types/package.json
+++ b/packages/devtools-types/package.json
@@ -23,11 +23,9 @@
     "url": "https://github.com/intlify/vue-i18n/issues"
   },
   "files": [
-    "index.js",
     "dist"
   ],
-  "main": "index.js",
-  "module": "dist/devtools-types.mjs",
+  "module": "dist/devtools-types.js",
   "types": "dist/devtools-types.d.ts",
   "dependencies": {
     "@intlify/core-base": "workspace:*",
@@ -39,24 +37,18 @@
   "buildOptions": {
     "name": "IntlifyDevToolsTypes",
     "formats": [
-      "mjs",
-      "cjs"
+      "mjs"
     ]
   },
   "exports": {
     ".": {
       "types": "./dist/devtools-types.d.ts",
-      "import": "./dist/devtools-types.mjs",
+      "import": "./dist/devtools-types.js",
       "node": {
         "import": {
-          "production": "./dist/devtools-types.prod.cjs",
-          "development": "./dist/devtools-types.mjs",
-          "default": "./dist/devtools-types.mjs"
-        },
-        "require": {
-          "production": "./dist/devtools-types.prod.cjs",
-          "development": "./dist/devtools-types.cjs",
-          "default": "./index.js"
+          "production": "./dist/devtools-types.prod.js",
+          "development": "./dist/devtools-types.js",
+          "default": "./dist/devtools-types.js"
         }
       }
     },
diff --git a/packages/message-compiler/index.js b/packages/message-compiler/index.js
deleted file mode 100644
index 5109c761e..000000000
--- a/packages/message-compiler/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/message-compiler.prod.cjs')
-} else {
-  module.exports = require('./dist/message-compiler.cjs')
-}
diff --git a/packages/message-compiler/package.json b/packages/message-compiler/package.json
index d94c560a0..60b444345 100644
--- a/packages/message-compiler/package.json
+++ b/packages/message-compiler/package.json
@@ -24,11 +24,9 @@
     "url": "https://github.com/intlify/vue-i18n/issues"
   },
   "files": [
-    "index.js",
     "dist"
   ],
-  "main": "index.js",
-  "module": "dist/message-compiler.mjs",
+  "module": "dist/message-compiler.js",
   "unpkg": "dist/message-compiler.global.js",
   "jsdelivr": "dist/message-compiler.global.js",
   "types": "dist/message-compiler.d.ts",
@@ -45,7 +43,6 @@
       "mjs",
       "mjs-node",
       "browser",
-      "cjs",
       "global"
     ],
     "enableFullBundleForEsmBrowser": true
@@ -53,18 +50,13 @@
   "exports": {
     ".": {
       "types": "./dist/message-compiler.d.ts",
-      "import": "./dist/message-compiler.mjs",
+      "import": "./dist/message-compiler.js",
       "browser": "./dist/message-compiler.esm-browser.js",
       "node": {
         "import": {
-          "production": "./dist/message-compiler.node.mjs",
-          "development": "./dist/message-compiler.node.mjs",
-          "default": "./dist/message-compiler.node.mjs"
-        },
-        "require": {
-          "production": "./dist/message-compiler.prod.cjs",
-          "development": "./dist/message-compiler.cjs",
-          "default": "./index.js"
+          "production": "./dist/message-compiler.node.js",
+          "development": "./dist/message-compiler.node.js",
+          "default": "./dist/message-compiler.node.js"
         }
       }
     },
diff --git a/packages/petite-vue-i18n/index.js b/packages/petite-vue-i18n/index.js
deleted file mode 100644
index a93b001de..000000000
--- a/packages/petite-vue-i18n/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/petite-vue-i18n.prod.cjs')
-} else {
-  module.exports = require('./dist/petite-vue-i18n.cjs')
-}
diff --git a/packages/petite-vue-i18n/package.json b/packages/petite-vue-i18n/package.json
index 97162f603..4291425c6 100644
--- a/packages/petite-vue-i18n/package.json
+++ b/packages/petite-vue-i18n/package.json
@@ -26,11 +26,9 @@
     "url": "https://github.com/intlify/vue-i18n/issues"
   },
   "files": [
-    "index.js",
     "dist"
   ],
-  "main": "index.js",
-  "module": "dist/petite-vue-i18n.mjs",
+  "module": "dist/petite-vue-i18n.js",
   "unpkg": "dist/petite-vue-i18n.global.js",
   "jsdelivr": "dist/petite-vue-i18n.global.js",
   "types": "dist/petite-vue-i18n.d.ts",
@@ -58,7 +56,6 @@
       "mjs-node-runtime",
       "browser",
       "browser-runtime",
-      "cjs",
       "global",
       "global-runtime"
     ]
@@ -66,18 +63,13 @@
   "exports": {
     ".": {
       "types": "./dist/petite-vue-i18n.d.ts",
-      "import": "./dist/petite-vue-i18n.mjs",
+      "import": "./dist/petite-vue-i18n.js",
       "browser": "./dist/petite-vue-i18n.esm-browser.js",
       "node": {
         "import": {
-          "production": "./dist/petite-vue-i18n.node.mjs",
-          "development": "./dist/petite-vue-i18n.node.mjs",
-          "default": "./dist/petite-vue-i18n.node.mjs"
-        },
-        "require": {
-          "production": "./dist/petite-vue-i18n.prod.cjs",
-          "development": "./dist/petite-vue-i18n.cjs",
-          "default": "./index.js"
+          "production": "./dist/petite-vue-i18n.node.js",
+          "development": "./dist/petite-vue-i18n.node.js",
+          "default": "./dist/petite-vue-i18n.node.js"
         }
       }
     },
diff --git a/packages/shared/index.js b/packages/shared/index.js
deleted file mode 100644
index 6aa3731fd..000000000
--- a/packages/shared/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/shared.prod.cjs')
-} else {
-  module.exports = require('./dist/shared.cjs')
-}
diff --git a/packages/shared/package.json b/packages/shared/package.json
index 385b1af68..9df8841ad 100644
--- a/packages/shared/package.json
+++ b/packages/shared/package.json
@@ -23,11 +23,9 @@
     "url": "https://github.com/intlify/vue-i18n/issues"
   },
   "files": [
-    "index.js",
     "dist"
   ],
-  "main": "index.js",
-  "module": "dist/shared.mjs",
+  "module": "dist/shared.js",
   "types": "dist/shared.d.ts",
   "engines": {
     "node": ">= 16"
@@ -36,25 +34,18 @@
     "name": "IntlifyShared",
     "formats": [
       "mjs",
-      "browser",
-      "cjs"
+      "browser"
     ]
   },
   "exports": {
     ".": {
       "types": "./dist/shared.d.ts",
-      "import": "./dist/shared.mjs",
+      "import": "./dist/shared.js",
       "browser": "./dist/shared.esm-browser.js",
       "node": {
         "import": {
-          "production": "./dist/shared.prod.cjs",
-          "development": "./dist/shared.mjs",
-          "default": "./dist/shared.mjs"
-        },
-        "require": {
-          "production": "./dist/shared.prod.cjs",
-          "development": "./dist/shared.cjs",
-          "default": "./index.js"
+          "development": "./dist/shared.js",
+          "default": "./dist/shared.js"
         }
       }
     },
diff --git a/packages/vue-i18n-core/index.js b/packages/vue-i18n-core/index.js
deleted file mode 100644
index ee69d2b71..000000000
--- a/packages/vue-i18n-core/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/vue-i18n-core.prod.cjs')
-} else {
-  module.exports = require('./dist/vue-i18n-core.cjs')
-}
diff --git a/packages/vue-i18n-core/package.json b/packages/vue-i18n-core/package.json
index c83192054..5a30c3c21 100644
--- a/packages/vue-i18n-core/package.json
+++ b/packages/vue-i18n-core/package.json
@@ -26,10 +26,8 @@
     "url": "https://github.com/intlify/vue-i18n/issues"
   },
   "files": [
-    "index.js",
     "dist"
   ],
-  "main": "index.js",
   "module": "dist/vue-i18n-core.mjs",
   "unpkg": "dist/vue-i18n-core.global.js",
   "jsdelivr": "dist/vue-i18n-core.global.js",
@@ -53,42 +51,29 @@
     "formats": [
       "mjs",
       "browser",
-      "cjs",
       "global"
     ]
   },
   "exports": {
     ".": {
       "types": "./dist/vue-i18n-core.d.ts",
-      "import": "./dist/vue-i18n-core.mjs",
+      "import": "./dist/vue-i18n-core.js",
       "browser": "./dist/vue-i18n-core.esm-browser.js",
       "node": {
         "import": {
-          "production": "./dist/vue-i18n-core.prod.cjs",
-          "development": "./dist/vue-i18n-core.mjs",
-          "default": "./dist/vue-i18n-core.mjs"
-        },
-        "require": {
-          "production": "./dist/vue-i18n-core.prod.cjs",
-          "development": "./dist/vue-i18n-core.cjs",
-          "default": "./index.js"
+          "development": "./dist/vue-i18n-core.js",
+          "default": "./dist/vue-i18n-core.js"
         }
       }
     },
     "./petite": {
       "types": "./dist/petite-vue-i18n-core.d.ts",
-      "import": "./dist/petite-vue-i18n-core.mjs",
+      "import": "./dist/petite-vue-i18n-core.js",
       "browser": "./dist/petite-vue-i18n-core.esm-browser.js",
       "node": {
         "import": {
-          "production": "./petite-dist/vue-i18n-core.prod.cjs",
-          "development": "./petite-dist/vue-i18n-core.mjs",
-          "default": "./dist/petite-vue-i18n-core.mjs"
-        },
-        "require": {
-          "production": "./dist/petite-vue-i18n-core.prod.cjs",
-          "development": "./dist/petite-vue-i18n-core.cjs",
-          "default": "./petite.js"
+          "development": "./petite-dist/vue-i18n-core.js",
+          "default": "./dist/petite-vue-i18n-core.js"
         }
       }
     },
diff --git a/packages/vue-i18n-core/petite.js b/packages/vue-i18n-core/petite.js
deleted file mode 100644
index 44e0a7a2b..000000000
--- a/packages/vue-i18n-core/petite.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/petite-vue-i18n-core.prod.cjs')
-} else {
-  module.exports = require('./dist/petite-vue-i18n-core.cjs')
-}
diff --git a/packages/vue-i18n/README.md b/packages/vue-i18n/README.md
index 1a8dcadfb..02cffe254 100644
--- a/packages/vue-i18n/README.md
+++ b/packages/vue-i18n/README.md
@@ -38,21 +38,13 @@ Internationalization plugin for Vue.js
 
 ### 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 externalize `vue-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`
-
-- **`vue-i18n(.runtime).node.mjs`**:
-  - For ES Moudles usage in Node.js
+- **`vue-i18n(.runtime).node.js`**:
+  - 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).mjs`
-    - **`vue-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`. 9.3+
+  - This module is proxy module of `vue-i18n(.runtime).js`
+    - **`vue-i18n.runtime.node.js`**: is runtime only
+    - **`vue-i18n.node.js`**: includes the runtime compiler
 
 
 ## For Bundler feature flags
diff --git a/packages/vue-i18n/index.js b/packages/vue-i18n/index.js
deleted file mode 100644
index 607e38d2b..000000000
--- a/packages/vue-i18n/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-'use strict'
-
-if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./dist/vue-i18n.prod.cjs')
-} else {
-  module.exports = require('./dist/vue-i18n.cjs')
-}
diff --git a/packages/vue-i18n/package.json b/packages/vue-i18n/package.json
index 052543701..1467c77f2 100644
--- a/packages/vue-i18n/package.json
+++ b/packages/vue-i18n/package.json
@@ -25,12 +25,10 @@
     "url": "https://github.com/intlify/vue-i18n/issues"
   },
   "files": [
-    "index.js",
     "dist",
     "vetur"
   ],
-  "main": "index.js",
-  "module": "dist/vue-i18n.mjs",
+  "module": "dist/vue-i18n.js",
   "unpkg": "dist/vue-i18n.global.js",
   "jsdelivr": "dist/vue-i18n.global.js",
   "types": "dist/vue-i18n.d.ts",
@@ -58,7 +56,6 @@
       "mjs-node-runtime",
       "browser",
       "browser-runtime",
-      "cjs",
       "global",
       "global-runtime"
     ]
@@ -66,18 +63,13 @@
   "exports": {
     ".": {
       "types": "./dist/vue-i18n.d.ts",
-      "import": "./dist/vue-i18n.mjs",
+      "import": "./dist/vue-i18n.js",
       "browser": "./dist/vue-i18n.esm-browser.js",
       "node": {
         "import": {
-          "production": "./dist/vue-i18n.node.mjs",
-          "development": "./dist/vue-i18n.node.mjs",
-          "default": "./dist/vue-i18n.node.mjs"
-        },
-        "require": {
-          "production": "./dist/vue-i18n.prod.cjs",
-          "development": "./dist/vue-i18n.cjs",
-          "default": "./index.js"
+          "production": "./dist/vue-i18n.node.js",
+          "development": "./dist/vue-i18n.node.js",
+          "default": "./dist/vue-i18n.node.js"
         }
       }
     },
diff --git a/rollup.config.mjs b/rollup.config.mjs
index 8b3be9ce9..dff6ab229 100644
--- a/rollup.config.mjs
+++ b/rollup.config.mjs
@@ -34,42 +34,36 @@ let hasTSChecked = false
 
 function resolveStubs(name, ns = '') {
   return {
-    [`dist/${ns}${name}.cjs`]: `${ns}${name}.cjs.js`,
-    [`dist/${ns}${name}.mjs`]: `${ns}${name}.esm-bundler.js`,
-    [`dist/${ns}${name}.runtime.mjs`]: `${ns}${name}.runtime.esm-bundler.js`,
-    [`dist/${ns}${name}.prod.cjs`]: `${ns}${name}.cjs.prod.js`
+    [`dist/${ns}${name}.js`]: `${ns}${name}.esm-bundler.js`,
+    [`dist/${ns}${name}.runtime.js`]: `${ns}${name}.runtime.esm-bundler.js`,
   }
 }
 
 function resolveOutputConfigs(name, ns = '') {
   return {
     mjs: {
-      file: `dist/${ns}${name}.mjs`,
+      file: `dist/${ns}${name}.js`,
       format: `es`
     },
     'mjs-node': {
-      file: `dist/${ns}${name}.node.mjs`,
+      file: `dist/${ns}${name}.node.js`,
       format: `es`
     },
     browser: {
       file: `dist/${ns}${name}.esm-browser.js`,
       format: `es`
     },
-    cjs: {
-      file: `dist/${ns}${name}.cjs`,
-      format: `cjs`
-    },
     global: {
       file: `dist/${ns}${name}.global.js`,
       format: `iife`
     },
     // runtime-only builds, for '@intlify/core' and 'vue-i18n' package only
     'mjs-runtime': {
-      file: `dist/${ns}${name}.runtime.mjs`,
+      file: `dist/${ns}${name}.runtime.js`,
       format: `es`
     },
     'mjs-node-runtime': {
-      file: `dist/${ns}${name}.runtime.node.mjs`,
+      file: `dist/${ns}${name}.runtime.node.js`,
       format: `es`
     },
     'browser-runtime': {
@@ -84,7 +78,7 @@ function resolveOutputConfigs(name, ns = '') {
 }
 
 const outputConfigs = resolveOutputConfigs(name)
-const defaultFormats = ['esm-bundler', 'cjs']
+const defaultFormats = ['esm-bundler']
 const inlineFormats = process.env.FORMATS && process.env.FORMATS.split(',')
 const packageFormats = inlineFormats || packageOptions.formats || defaultFormats
 
@@ -112,12 +106,6 @@ if (process.env.NODE_ENV === 'production') {
     if (packageOptions.prod === false) {
       return
     }
-    if (format === 'cjs') {
-      packageConfigs.push(createProductionConfig(format, name))
-      if (name === 'vue-i18n-core') {
-        packageConfigs.push(createProductionConfig(format, name, 'petite-'))
-      }
-    }
     if (/^(global|browser)(-runtime)?/.test(format)) {
       packageConfigs.push(createMinifiedConfig(format, outputConfigs[format]))
       if (name === 'vue-i18n-core') {
@@ -158,7 +146,7 @@ function createConfig(format, _output, plugins = []) {
     process.env.__DEV__ === 'false' || /\.prod\.[cm]?js$/.test(output.file)
   const isBundlerESMBuild = /mjs/.test(format)
   const isBrowserESMBuild = /browser/.test(format)
-  const isNodeBuild = output.file.includes('.node.') || format === 'cjs'
+  const isNodeBuild = output.file.includes('.node.')
   const isGlobalBuild = /global/.test(format)
   const isRuntimeOnlyBuild = /runtime/.test(format)
   const isLite = /petite-vue-i18n/.test(output.file)
@@ -209,10 +197,7 @@ function createConfig(format, _output, plugins = []) {
           ...Object.keys(pkg.peerDependencies || {})
         ]
 
-  const nodePlugins =
-    // packageOptions.enableNonBrowserBranches && format !== 'cjs'
-    format !== 'cjs'
-      ? [
+  const nodePlugins = [
           require('@rollup/plugin-node-resolve').nodeResolve(),
           require('@rollup/plugin-commonjs')({
             sourceMap: false
@@ -220,7 +205,6 @@ function createConfig(format, _output, plugins = []) {
           require('rollup-plugin-node-builtins')(),
           require('rollup-plugin-node-globals')()
         ]
-      : []
 
   return {
     input: resolve(entryFile),
@@ -253,10 +237,7 @@ function createConfig(format, _output, plugins = []) {
           const stub = stubs[rawFile]
           if (!stub) return
 
-          const contents =
-            format === 'cjs'
-              ? `module.exports = require('../${rawFile}')`
-              : `export * from '../${rawFile}'`
+          const contents = `export * from '../${rawFile}'`
 
           await fs.writeFile(resolve(`dist/${stub}`), contents)
           console.log(`created stub ${pc.bold(`dist/${stub}`)}`)
@@ -391,15 +372,6 @@ function createReplacePlugin(
   })
 }
 
-function createProductionConfig(format, name, ns = '') {
-  const extension = format === 'cjs' || format === 'mjs' ? format : 'js'
-  const descriptor = format === 'cjs' || format === 'mjs' ? '' : `.${format}`
-  return createConfig(format, {
-    file: `dist/${ns}${name}${descriptor}.prod.${extension}`,
-    format: outputConfigs[format].format
-  })
-}
-
 function createMinifiedConfig(format, output) {
   const newOutput = {
     file: output.file.replace(/\.js$/, '.prod.js'),
diff --git a/scripts/build-rolldown.ts b/scripts/build-rolldown.ts
index 96c7ec98a..533b17beb 100644
--- a/scripts/build-rolldown.ts
+++ b/scripts/build-rolldown.ts
@@ -3,14 +3,14 @@ Produces production builds and stitches together d.ts files.
 
 To specify the package to build, simply pass its name and the desired build
 formats to output (defaults to `buildOptions.formats` specified in that package,
-or "esm,cjs"):
+or "esm"):
 
 ```
 # name supports fuzzy match. will build all packages with name containing "core-base":
 pnpm build core-base
 
 # specify the format to output
-pnpm build core --formats cjs
+pnpm build core --formats mjs
 ```
 */
 
diff --git a/scripts/build.ts b/scripts/build.ts
index 3ca8614c8..66e1bf15a 100644
--- a/scripts/build.ts
+++ b/scripts/build.ts
@@ -3,14 +3,14 @@ Produces production builds and stitches together d.ts files.
 
 To specify the package to build, simply pass its name and the desired build
 formats to output (defaults to `buildOptions.formats` specified in that package,
-or "esm,cjs"):
+or "esm"):
 
 ```
 # name supports fuzzy match. will build all packages with name containing "core-base":
 pnpm build core-base
 
 # specify the format to output
-pnpm build core --formats cjs
+pnpm build core --formats mjs
 ```
 */
 
diff --git a/scripts/dev.ts b/scripts/dev.ts
index 7caf00bb0..b45459ce8 100644
--- a/scripts/dev.ts
+++ b/scripts/dev.ts
@@ -9,7 +9,7 @@ formats to watch (defaults to "global"):
 pnpm dev core-base
 
 # specify the format to output
-pnpm dev core --formats cjs
+pnpm dev core --formats mjs
 
 # Can also drop all __DEV__ blocks with:
 __DEV__=false pnpm run dev
diff --git a/scripts/rolldown.ts b/scripts/rolldown.ts
index ceb700c64..94feba102 100644
--- a/scripts/rolldown.ts
+++ b/scripts/rolldown.ts
@@ -55,10 +55,8 @@ export function createConfigsForPackage({
 
   function resolveStubs(name: string, ns = '') {
     return {
-      [`dist/${ns}${name}.cjs`]: `${ns}${name}.cjs.js`,
-      [`dist/${ns}${name}.mjs`]: `${ns}${name}.esm-bundler.js`,
-      [`dist/${ns}${name}.runtime.mjs`]: `${ns}${name}.runtime.esm-bundler.js`,
-      [`dist/${ns}${name}.prod.cjs`]: `${ns}${name}.cjs.prod.js`
+      [`dist/${ns}${name}.js`]: `${ns}${name}.esm-bundler.js`,
+      [`dist/${ns}${name}.runtime.js`]: `${ns}${name}.runtime.esm-bundler.js`
     }
   }
 
@@ -68,32 +66,28 @@ export function createConfigsForPackage({
   ): Record<string, OutputOptions> {
     return {
       mjs: {
-        file: resolve(`dist/${ns}${name}.mjs`),
+        file: resolve(`dist/${ns}${name}.js`),
         format: `es`
       },
       'mjs-node': {
-        file: resolve(`dist/${ns}${name}.node.mjs`),
+        file: resolve(`dist/${ns}${name}.node.js`),
         format: `es`
       },
       browser: {
         file: resolve(`dist/${ns}${name}.esm-browser.js`),
         format: `es`
       },
-      cjs: {
-        file: resolve(`dist/${ns}${name}.cjs`),
-        format: `cjs`
-      },
       global: {
         file: resolve(`dist/${ns}${name}.global.js`),
         format: `iife`
       },
       // runtime-only builds, for '@intlify/core' and 'vue-i18n' package only
       'mjs-runtime': {
-        file: resolve(`dist/${ns}${name}.runtime.mjs`),
+        file: resolve(`dist/${ns}${name}.runtime.js`),
         format: `es`
       },
       'mjs-node-runtime': {
-        file: resolve(`dist/${ns}${name}.runtime.node.mjs`),
+        file: resolve(`dist/${ns}${name}.runtime.node.js`),
         format: `es`
       },
       'browser-runtime': {
@@ -114,10 +108,7 @@ export function createConfigsForPackage({
 
   const outputConfigs = resolveOutputConfigs(name)
 
-  const resolvedFormats = (
-    formats ||
-    packageOptions.formats || ['esm-bundler', 'cjs']
-  )
+  const resolvedFormats = (formats || packageOptions.formats || ['esm-bundler'])
     .filter(Boolean)
     .filter((format: string) => outputConfigs[format])
 
@@ -144,12 +135,6 @@ export function createConfigsForPackage({
       if (packageOptions.prod === false) {
         return
       }
-      if (format === 'cjs') {
-        packageConfigs.push(createProductionConfig(format, name))
-        if (name === 'vue-i18n-core') {
-          packageConfigs.push(createProductionConfig(format, name, 'petite-'))
-        }
-      }
       if (/^(global|browser)(-runtime)?/.test(format)) {
         packageConfigs.push(createMinifiedConfig(format, outputConfigs[format]))
         if (name === 'vue-i18n-core') {
@@ -178,9 +163,7 @@ export function createConfigsForPackage({
     const isBundlerESMBuild = /mjs/.test(format)
     const isBrowserESMBuild =
       /browser/.test(format) && !packageOptions.enableNonBrowserBranches
-    // const isCJSBuild = format === 'cjs'
-    const isNodeBuild =
-      String(output.file).includes('.node.') || format === 'cjs'
+    const isNodeBuild = String(output.file).includes('.node.')
     const isGlobalBuild = /global/.test(format)
     const isRuntimeOnlyBuild = /runtime/.test(format)
     const isLite = /petite-vue-i18n/.test(String(output.file))
@@ -189,9 +172,6 @@ export function createConfigsForPackage({
     output.sourcemap = sourceMap
     output.banner = banner
     output.externalLiveBindings = false
-    // if (isCJSBuild) {
-    //   output.esModule = true
-    // }
     if (
       name === 'vue-i18n' ||
       name === 'vue-i18n-core' ||
@@ -317,11 +297,9 @@ export function createConfigsForPackage({
     }
 
     function resolveNodePlugins() {
-      const nodePlugins =
-        (format === 'cjs' && Object.keys(pkg.devDependencies || {}).length) ||
-        packageOptions.enableNonBrowserBranches
-          ? [...(format === 'cjs' ? [] : [polyfillNode()])]
-          : []
+      const nodePlugins = packageOptions.enableNonBrowserBranches
+        ? [...[polyfillNode()]]
+        : []
       return nodePlugins
     }
 
@@ -331,7 +309,7 @@ export function createConfigsForPackage({
       // used alone.
       external: resolveExternal(),
       define: resolveDefine(),
-      platform: format === 'cjs' ? 'node' : 'browser',
+      platform: 'browser',
       resolve: {
         alias: entries
       },
@@ -351,10 +329,7 @@ export function createConfigsForPackage({
             }
 
             const filename = path.basename(rawFile)
-            const contents =
-              format === 'cjs'
-                ? `module.exports = require('./${filename}')`
-                : `export * from './${filename}'`
+            const contents = `export * from './${filename}'`
 
             await fs.writeFile(stub, contents)
             // console.log(`created stub ${pc.bold(path.join('packages', target, 'dist', path.basename(stub)))}`)
@@ -369,19 +344,6 @@ export function createConfigsForPackage({
     }
   }
 
-  function createProductionConfig(
-    format: string,
-    name: string,
-    ns = ''
-  ): RolldownOptions {
-    const extension = format === 'cjs' || format === 'mjs' ? format : 'js'
-    const descriptor = format === 'cjs' || format === 'mjs' ? '' : `.${format}`
-    return createConfig(format, {
-      file: resolve(`dist/${ns}${name}${descriptor}.prod.${extension}`),
-      format: outputConfigs[format].format
-    })
-  }
-
   function createMinifiedConfig(
     format: string,
     output: OutputOptions
diff --git a/scripts/utils.ts b/scripts/utils.ts
index 564bcf324..b938e5daf 100644
--- a/scripts/utils.ts
+++ b/scripts/utils.ts
@@ -113,8 +113,7 @@ export async function checkSizeDistFiles(target: string) {
   return dirs.filter(file => /^(message-compiler|core|vue-i18n|petite-vue-i18n)/.test(file))
     .filter(file => !/^core-base/.test(file))
     .filter(file => !/^vue-i18n-core/.test(file))
-    .filter(file => /prod.(cjs|js)$/.test(file))
-    .filter(file => !/cjs.prod.js$/.test(file))
+    .filter(file => /prod\.js$/.test(file))
 }
 
 export async function readJson(path: string) {