@babel/plugin-transform-unicode-regex

What is @babel/plugin-transform-unicode-regex?

The @babel/plugin-transform-unicode-regex package is a plugin for Babel, a JavaScript compiler, that transforms Unicode regular expressions into equivalent ES5 syntax. This is particularly useful for ensuring compatibility with older environments that do not support Unicode property escapes in regular expressions.

What are @babel/plugin-transform-unicode-regex's main functionalities?

Transform Unicode Regular Expressions

This plugin transforms Unicode regular expressions like the one above into an ES5-compatible syntax. The 'u' flag in the regular expression indicates that it's using Unicode mode, which is not supported in older JavaScript environments. The plugin will convert this to a form that can be understood by these environments.

const regex = /\p{Script=Greek}/u;

Other packages similar to @babel/plugin-transform-unicode-regex

regexpu-core

regexpu-core is a package that also compiles Unicode regular expressions to ES5. It is similar to @babel/plugin-transform-unicode-regex but can be used independently of Babel. It provides a low-level API for transforming regular expressions and is used by Babel itself.

babel-plugin-transform-es2015-unicode-regex

This is a legacy Babel plugin that was used to transform Unicode regular expressions in ES2015 (ES6) code to be ES5-compatible. It has similar functionality to @babel/plugin-transform-unicode-regex but is specific to the ES2015 preset. It is now deprecated in favor of the unified @babel/preset-env.

README

@babel/plugin-transform-unicode-regex

Compile ES2015 Unicode regex to ES5

See our website @babel/plugin-transform-unicode-regex for more information.

Install

Using npm:

npm install --save-dev @babel/plugin-transform-unicode-regex

or using yarn:

yarn add @babel/plugin-transform-unicode-regex --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)