TypeScript to JavaScript Converter
Transpile TypeScript to clean, browser-ready JavaScript with AI-powered conversion. Strips type annotations, removes interface declarations, and erases generic type parameters while preserving runtime logic. Compiles decorators to equivalent function calls, converts enums to plain objects, and outputs modern ES2020+ JavaScript compatible with all major browsers and Node.js environments.
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Issue Description
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How It Works
- Step 1: Paste your TypeScript source code including type annotations, interface declarations, generic classes, enum definitions, and decorator usage.
- Step 2: The AI identifies TypeScript-specific syntax like type aliases, union types, intersection types, and compile-time-only constructs that need removal.
- Step 3: Advanced transpilation strips all type information while preserving JavaScript logic, converts TypeScript enums to objects, and compiles decorators to runtime code.
- Step 4: Download clean, optimized JavaScript code ready for immediate browser or Node.js deployment without requiring build tools.
TypeScript vs JavaScript: What Gets Removed
| Feature | TypeScript | JavaScript |
|---|---|---|
| Type Annotations | Required for type safety | Removed entirely |
| Interfaces | Compile-time contracts | Erased, no runtime presence |
| Generics | Type-safe collections | Type parameters removed |
| Enums | Strongly-typed constants | Converted to objects or unions |
| Decorators | Metadata annotations | Transpiled to function calls |
Code Conversion Examples
Example 1: Type Annotations and Interfaces
interface User {
id: number;
username: string;
email: string;
roles: string[];
}
type UserID = number;
type UserMap = Map<UserID, User>;
class UserService {
private users: UserMap;
constructor() {
this.users = new Map<UserID, User>();
}
addUser(user: User): void {
this.users.set(user.id, user);
}
getUser(id: UserID): User | undefined {
return this.users.get(id);
}
hasRole(userId: UserID, role: string): boolean {
const user = this.getUser(userId);
return user?.roles.includes(role) ?? false;
}
} class UserService {
constructor() {
this.users = new Map();
}
addUser(user) {
this.users.set(user.id, user);
}
getUser(id) {
return this.users.get(id);
}
hasRole(userId, role) {
const user = this.getUser(userId);
return user?.roles.includes(role) ?? false;
}
} Key Changes:
All TypeScript type annotations are stripped cleanly—interfaces (User), type aliases (UserID, UserMap), generic type parameters (Map<UserID, User>), and return types (void, boolean) disappear. The private access modifier is removed as JavaScript uses # for private fields or relies on conventions. Optional chaining (?.) and nullish coalescing (??) operators remain as they're JavaScript features, not TypeScript-specific.
Example 2: Enums and Generics
enum Status {
Pending = 'PENDING',
Approved = 'APPROVED',
Rejected = 'REJECTED'
}
enum Priority {
Low = 1,
Medium = 2,
High = 3
}
class Task<T> {
private data: T;
private status: Status;
private priority: Priority;
constructor(data: T, priority: Priority = Priority.Medium) {
this.data = data;
this.status = Status.Pending;
this.priority = priority;
}
approve(): void {
this.status = Status.Approved;
}
getData(): T {
return this.data;
}
getStatusInfo(): { status: Status; priority: Priority } {
return {
status: this.status,
priority: this.priority
};
}
}
const task = new Task<string>('Review pull request', Priority.High);
task.approve(); const Status = {
Pending: 'PENDING',
Approved: 'APPROVED',
Rejected: 'REJECTED'
};
const Priority = {
Low: 1,
Medium: 2,
High: 3
};
class Task {
constructor(data, priority = Priority.Medium) {
this.data = data;
this.status = Status.Pending;
this.priority = priority;
}
approve() {
this.status = Status.Approved;
}
getData() {
return this.data;
}
getStatusInfo() {
return {
status: this.status,
priority: this.priority
};
}
}
const task = new Task('Review pull request', Priority.High);
task.approve(); Key Changes:
TypeScript enums compile to plain JavaScript objects preserving runtime values. String enums (Status) and numeric enums (Priority) both become frozen object literals. Generic type parameters (<T>) are completely erased—the class works with any type at runtime. Type annotations on methods (void, T, object shapes) are stripped while keeping the actual implementation logic intact. Default parameters remain unchanged as they're standard JavaScript.
Frequently Asked Questions
Can I configure the target ECMAScript version?
The converter outputs modern ES2020+ JavaScript by default. Target customization (ES5 for legacy browsers, ESNext for cutting-edge features) requires manual tsconfig.json-style configuration post-conversion. The tool prioritizes readable modern JavaScript over compatibility transformations like downleveling async/await to generators.
Is my TypeScript code processed on external servers?
Yes. AI-powered conversion requires server-side processing for intelligent type stripping and syntax transformation. Your TypeScript source is transmitted over HTTPS, converted, then discarded. We do not store code. For simple type stripping without AI, use the official TypeScript compiler (tsc) locally.
What TypeScript features cannot be converted?
Ambient declarations (declare), triple-slash directives, and .d.ts type definition files have no JavaScript equivalent. Complex conditional types and mapped types used in type gymnastics are erased without runtime representation. The tool excels at application code but struggles with library typings and advanced type-level programming.