@babel/plugin-transform-flow-strip-types

What is @babel/plugin-transform-flow-strip-types?

The @babel/plugin-transform-flow-strip-types npm package is a plugin for Babel, a JavaScript compiler, that removes type annotations from Flow, a static type checker for JavaScript. This allows developers to write type-safe code during development and strip out these annotations for production builds, resulting in clean JavaScript that can be executed in environments that do not support Flow.

What are @babel/plugin-transform-flow-strip-types's main functionalities?

Stripping Flow Type Annotations

This feature removes Flow type annotations from your JavaScript files, converting typed code into plain JavaScript. The code sample shows a function with Flow types that are stripped out after transformation.

import { foo } from 'bar';
function square(n: number): number {
  return n * n;
}
// Transformed to:
import { foo } from 'bar';
function square(n) {
  return n * n;
}

Other packages similar to @babel/plugin-transform-flow-strip-types

@babel/plugin-transform-typescript

Similar to @babel/plugin-transform-flow-strip-types, this Babel plugin strips TypeScript annotations from the code. While both plugins serve a similar purpose of removing type annotations, they cater to different type systems: Flow for the former and TypeScript for the latter.

babel-plugin-transform-flow-comments

This plugin also deals with Flow types but instead of stripping them, it converts them into comments. This can be useful for preserving type annotations in the transpiled output without affecting the runtime behavior.

README

@babel/plugin-transform-flow-strip-types

Strip flow type annotations from your output code.

See our website @babel/plugin-transform-flow-strip-types for more information.

Install

Using npm:

npm install --save-dev @babel/plugin-transform-flow-strip-types

or using yarn:

yarn add @babel/plugin-transform-flow-strip-types --dev

Changelog

v7.27.1 (2025-04-30)

:eyeglasses: Spec Compliance

• babel-parser
  • #17254 Allow using of as lexical declaration within for (@JLHwung)
  • #17230 Disallow get/set in TSPropertySignature (@JLHwung)
• babel-parser, babel-types
  • #17193 Stricter TSImportType options parsing (@JLHwung)

:bug: Bug Fix

• babel-plugin-proposal-destructuring-private, babel-plugin-proposal-do-expressions, babel-traverse
  • #17137 fix: do expressions should allow early exit (@kermanx)
• babel-helper-wrap-function, babel-plugin-transform-async-to-generator
  • #17251 Fix: propagate argument evaluation errors through async promise chain (@magic-akari)
• babel-helper-remap-async-to-generator, babel-plugin-transform-async-to-generator
  • #17231 fix apply()/call() annotated as pure (@Lacsw)
• babel-helper-fixtures, babel-parser
  • #17233 Create ChainExpression within TSInstantiationExpression (@JLHwung)
• babel-generator, babel-parser
  • #17226 Fill optional AST properties when both estree and typescript parser plugin are enabled (Part 2) (@JLHwung)
• babel-parser
  • #17224 Fill optional AST properties when both estree and typescript parser plugin are enabled (Part 1) (@JLHwung)
  • #17080 Fix start of TSParameterProperty (@JLHwung)
• babel-compat-data, babel-preset-env
  • #17228 Update firefox bugfix compat data (@JLHwung)
• babel-traverse
  • #17156 fix: Objects and arrays with multiple references should not be evaluated (@liuxingbaoyu)
• babel-generator
  • #17216 Fix: support const type parameter in generator (@JLHwung)

:nail_care: Polish

• babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining, babel-plugin-proposal-decorators, babel-plugin-transform-arrow-functions, babel-plugin-transform-class-properties, babel-plugin-transform-destructuring, babel-plugin-transform-object-rest-spread, babel-plugin-transform-optional-chaining, babel-plugin-transform-parameters, babel-traverse
  • #17221 Reduce generated names size for the 10th-11th (@nicolo-ribaudo)

:house: Internal

• babel-runtime-corejs2, babel-runtime-corejs3, babel-runtime
  • #17263 Remove unused regenerator-runtime dep in @babel/runtime (@nicolo-ribaudo)
• babel-compat-data, babel-preset-env
  • #17256 Tune plugin compat data (@JLHwung)
• babel-compat-data, babel-standalone
  • #17236 migrate babel-compat-data build script to mjs (@JLHwung)
• Other
  • #17232 Bump typescript-eslint to 8.29.1 (@JLHwung)
  • #17219 test: add basic typescript-eslint integration tests (@JLHwung)
  • #17205 Inline regenerator in the relevant packages (@nicolo-ribaudo)
• babel-register
  • #16844 Migrate @babel/register to cts (@liuxingbaoyu)
• babel-cli, babel-compat-data, babel-core, babel-generator, babel-helper-compilation-targets, babel-helper-fixtures, babel-helper-module-imports, babel-helper-module-transforms, babel-helper-plugin-test-runner, babel-helper-transform-fixture-test-runner, babel-helpers, babel-node, babel-parser, babel-plugin-transform-modules-amd, babel-plugin-transform-modules-commonjs, babel-plugin-transform-modules-systemjs, babel-plugin-transform-modules-umd, babel-plugin-transform-react-display-name, babel-plugin-transform-regenerator, babel-plugin-transform-runtime, babel-plugin-transform-typeof-symbol, babel-plugin-transform-typescript, babel-preset-env, babel-register, babel-standalone, babel-types
  • #17207 Enforce node protocol import (@JLHwung)
• babel-plugin-transform-regenerator
  • #17205 Inline regenerator in the relevant packages (@nicolo-ribaudo)
  • #17205 Inline regenerator in the relevant packages (@nicolo-ribaudo)
• babel-helpers, babel-plugin-transform-async-generator-functions, babel-plugin-transform-regenerator, babel-preset-env, babel-runtime-corejs3
  • #17205 Inline regenerator in the relevant packages (@nicolo-ribaudo)
• babel-helpers, babel-plugin-transform-regenerator
  • #17205 Inline regenerator in the relevant packages (@nicolo-ribaudo)
  • #17205 Inline regenerator in the relevant packages (@nicolo-ribaudo)
• babel-helpers
  • #17205 Inline regenerator in the relevant packages (@nicolo-ribaudo)

:microscope: Output optimization

• babel-helpers, babel-plugin-transform-modules-commonjs, babel-runtime-corejs3
  • #16538 Reduce interopRequireWildcard size (@liuxingbaoyu)
• babel-helpers, babel-plugin-transform-async-generator-functions, babel-plugin-transform-regenerator, babel-preset-env, babel-runtime-corejs3
  • #17213 Reduce regeneratorRuntime size (@liuxingbaoyu)