# What changed in @babel/parser

> 50 changes in @babel/parser 8 from its official release notes, upgrade guides and advisories: 47 breaking, 1 deprecations, 1 new APIs and options. Each one cited. Sources checked 2026-10-23. HTML: https://unstale.sh/npm/@babel/parser/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## @babel/parser 8

### Breaking changes

- BigIntLiteral.value is a bigint rather than a string; use toString() for a string representation, and provide a serializer if storing the AST as JSON. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The typeParameters field is renamed to typeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The superTypeParameters field is renamed to superTypeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The superTypeParameters field is renamed to superTypeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- TSParenthesizedType is no longer generated unless createParenthesizedExpression is enabled; node.extra.parenthesized can identify parentheses when it is false. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The decimal parser plugin is removed because the latest proposal no longer includes the syntax. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- The parser plugin for the obsolete import attributes syntax using assert is removed. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- The error code for OptionalBindingPattern is renamed to PatternIsOptional, aligning Flow and TypeScript parser error codes. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- Babel is shipped as native ECMAScript modules. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- Remove the classFeatures option; class properties AST output compatible with ESLint 8 is now enabled by default. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- The parser plugin for the obsolete import attributes syntax using assert is removed. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- Dynamic import() is represented by an ImportExpression node instead of a CallExpression with an Import callee. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The importReflection parser plugin is removed; use sourcePhaseImports and replace the source modifier module with source. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- The characters {, }, <, and > are disallowed in JSX text; represent them with JSX expressions instead. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- The typeParameters field is renamed to typeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The packed locations option is removed. (8.0.0) — [release notes](https://github.com/babel/babel/blob/HEAD/CHANGELOG.md)
- The typeParameters field is renamed to typeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- ObjectProperty nodes no longer include extra.shorthand; use node.shorthand instead. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- Babel 8 packages require Node.js ^22.18.0 || >=24.11.0; Babel itself no longer runs on older Node versions. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- The typeParameters field is renamed to typeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- Private names such as #priv are returned as a single privateName token instead of separate # and name tokens. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- Sequence expressions inside JSX attributes are disallowed; parenthesize the sequence expression. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- Use sourcePhaseImports instead of importReflection for source phase imports, and use source rather than module in import declarations. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration)
- Template literal segments are tokenized as templateNonTail or templateTail rather than the generic template token. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The updateContext field is removed from token types returned when the tokens option is enabled. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The parameters field is renamed to params. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The return type field typeAnnotation is renamed to returnType. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The parameters field is renamed to params. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The return type field typeAnnotation is renamed to returnType. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The parameters field is renamed to params. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The return type field typeAnnotation is renamed to returnType. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- Enum members are now contained in a TSEnumBody node under the body field. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- This node is split into TSClassImplements and TSInterfaceHeritage; qualified-name expressions are represented as MemberExpression nodes. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The parameters field is renamed to params. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The return type field typeAnnotation is renamed to returnType. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- An exported TSImportEqualsDeclaration is now nested in an ExportNamedDeclaration, and its isExport field is removed; detect exports through the parent path. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The argument field is renamed to source. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The typeParameters field is renamed to typeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The typeParameters field is renamed to typeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The typeParameter property is flattened into key and constraint properties on TSMappedType. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The parameters field is renamed to params. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The return type field typeAnnotation is renamed to returnType. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- A dotted namespace name such as namespace X.Y is represented as one TSModuleDeclaration with a TSQualifiedName, rather than nested TSModuleDeclaration nodes. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- Interpolated template literal types now produce a TSTemplateLiteralType node. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- TSTypeParameter.name is an Identifier node rather than a plain string. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The typeParameters field is renamed to typeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)
- The typeParameters field is renamed to typeArguments. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)

### Deprecations

- The legacy import() AST can be requested with false, but that AST is deprecated and the parser option will be removed in Babel 9. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)

### New APIs and options

- When both estree and typescript parser plugins are enabled, the parser creates TSAbstractMethodDefinition and TSPropertyDefinition nodes. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)

### Fixes and other changes

- TSTypeQuery.exprName can be a ThisExpression for typeof this, rather than an Identifier named this. (8.0.0) — [upgrade guide](https://babel.dev/docs/v8-migration-api)