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JSDoc tag

@override

  • Checked by TypeScript
  • Tested with TypeScript 5.9

@override on a class member says it replaces a member of the base class. TypeScript checks the claim: an @override on a method the base class does not have is an error (TS4122), which catches a rename in the base class that left a subclass method orphaned.

With noImplicitOverride in jsconfig.json, the check also runs the other way: every member that overrides one in the base class must carry the tag (TS4119). That is the JavaScript form of TypeScript's override keyword, with the same noImplicitOverride option.

At a glance

Use JSDoc in a .js file TypeScript in a .ts file
An overriding method /** @override */ area() { … } override area() { … }
Require it everywhere "noImplicitOverride": true "noImplicitOverride": true

Examples

shapes.js shapes.ts TypeScript 5.9.3 TypeScript 5.9.3, run 21 October 2026: No errors. 6.0.3 TypeScript 6.0.3, run 21 October 2026: the same as 5.9.3. No errors. 7.0.2 TypeScript 7.0.2, run 21 October 2026: the same as 5.9.3. No errors. checked 21 October 2026 
export class Shape {
  /** @returns {number} */
  area() {
    return 0;
  }
}

export class Circle extends Shape {
  /** @param {number} radius */
  constructor(radius) {
    super();
    this.radius = radius;
  }

  /** @override */
  area() {
    return Math.PI * this.radius ** 2;
  }
}
export class Shape {
  area(): number {
    return 0;
  }
}

export class Circle extends Shape {
  radius: number;

  constructor(radius: number) {
    super();
    this.radius = radius;
  }

  override area() {
    return Math.PI * this.radius ** 2;
  }
}
Marking overriding methods with @override.
jsconfig.json for this example 
{
  "compilerOptions": {
    "checkJs": true,
    "noEmit": true,
    "strict": true,
    "noImplicitOverride": true,
    "target": "es2022",
    "module": "nodenext",
    "types": []
  },
  "include": ["*.js"]
}
shapes.js Error confirmed 5.9.3 TypeScript 5.9.3, run 21 October 2026: shapes.js(12,3): error TS4119: This member must have a JSDoc comment with an '@override' tag because it overrides a member in the base class 'Shape'. 6.0.3 TypeScript 6.0.3, run 21 October 2026: the same as 5.9.3. shapes.js(12,3): error TS4119: This member must have a JSDoc comment with an '@override' tag because it overrides a member in the base class 'Shape'. 7.0.2 TypeScript 7.0.2, run 21 October 2026: the same as 5.9.3. shapes.js(12,3): error TS4119: This member must have a JSDoc comment with an '@override' tag because it overrides a member in the base class 'Shape'. checked 21 October 2026 
export class Shape {
  /** @returns {number} */
  area() {
    return 0;
  }
}

export class Square extends Shape {
  side = 2;

  area() {error TS4119: This member must have a JSDoc comment with an '@override' tag because it overrides a member in the base class 'Shape'.
    return this.side ** 2;
  }
}
With noImplicitOverride, a missing @override is an error.
jsconfig.json for this example 
{
  "compilerOptions": {
    "checkJs": true,
    "noEmit": true,
    "strict": true,
    "noImplicitOverride": true,
    "target": "es2022",
    "module": "nodenext",
    "types": []
  },
  "include": ["*.js"]
}
shapes.js Error confirmed 5.9.3 TypeScript 5.9.3, run 21 October 2026: shapes.js(13,3): error TS4122: This member cannot have a JSDoc comment with an '@override' tag because it is not declared in the base class 'Shape'. 6.0.3 TypeScript 6.0.3, run 21 October 2026: the same as 5.9.3. shapes.js(13,3): error TS4122: This member cannot have a JSDoc comment with an '@override' tag because it is not declared in the base class 'Shape'. 7.0.2 TypeScript 7.0.2, run 21 October 2026: the same as 5.9.3. shapes.js(13,3): error TS4122: This member cannot have a JSDoc comment with an '@override' tag because it is not declared in the base class 'Shape'. checked 21 October 2026 
export class Shape {
  /** @returns {number} */
  area() {
    return 0;
  }
}

export class Square extends Shape {
  side = 2;

  /** @override */
  perimeter() {error TS4122: This member cannot have a JSDoc comment with an '@override' tag because it is not declared in the base class 'Shape'.
    return this.side * 4;
  }
}
An @override on a method the base class does not have.
jsconfig.json for this example 
{
  "compilerOptions": {
    "checkJs": true,
    "noEmit": true,
    "strict": true,
    "target": "es2022",
    "module": "nodenext",
    "types": []
  },
  "include": ["*.js"]
}

The two checks

The check on tagged members is always on: the third example has no noImplicitOverride and still fails, because perimeter() overrides nothing. The check on untagged members needs the option: the second example sets it, and the area() without a tag fails.

The JavaScript messages name the JSDoc tag: "This member must have a JSDoc comment with an '@override' tag…" and "This member cannot have a JSDoc comment with an '@override' tag…". In a .ts file the same checks talk about the override modifier.

Where the tag goes

In the member's own JSDoc comment, on the lines above it. In our tests, a comment written on the same line as the class's opening brace (class Circle extends Shape { /** @override */ area() …) was not attached to the method, so the tag had no effect.

Gotchas

  • The override keyword is TypeScript syntax: in a .js file it is an error (TS8009).
  • The override keyword and noImplicitOverride arrived with TypeScript 4.3; the release notes do not date the JSDoc tag, and the examples on this page are checked with TypeScript 5.9.

Questions

Do I need noImplicitOverride to use @override?

No. A wrong @override is reported without it. The option only adds the reverse check, that every override is tagged.

  • JSDoc tag

    @extends and @augments

    @extends (or @augments) gives a JavaScript class's generic base its type arguments: @extends {Map<string, number>} with extends Map. Syntax and examples.

  • JSDoc tag

    @class and @constructor

    @class and @constructor mark a JavaScript function as a constructor, so TypeScript requires new and types this. When you need them, and when a class is simpler.

  • JSDoc tag

    @abstract

    TypeScript does not act on the JSDoc @abstract tag, so new Shape() still passes. What tsc does instead, and how to build an abstract class in JavaScript.

  • jsconfig.json option

    noImplicitOverride

    noImplicitOverride requires an @override tag on each method that replaces a base-class method, so renaming the base method cannot silently break it.

  • TypeScript error

    TS4119: An override without the @override tag

    TS4119 means noImplicitOverride is on and a subclass method replaces a base class method without an @override tag. Add the tag above the method.

  • TypeScript error

    TS4122: @override on a member the base class does not have

    TS4122 means a member is tagged @override but the base class has no member of that name: a typo, a rename in the base, or a new method. Fix or drop the tag.

Sources

Last reviewed 20 October 2026.