JS to TSX Converter

Convert JavaScript React components to TypeScript TSX with AI — free, instant, no login required.

JS to TSX conversion migrates plain JavaScript React components to fully typed TypeScript — adding prop interfaces, typed useState and useRef hooks, and event handler types. JS2TS automates the entire migration with AI, turning hours of manual typing into seconds.

Paste your code, then click Convert

TSX

How to use this tool?

This AI-powered converter migrates plain JavaScript React components to fully typed TypeScript TSX files. Follow these steps:

Paste your JavaScript React component code into the input box on the left.
Click the "Convert" button. The AI adds TypeScript interfaces, typed hooks, and event handler types.
Copy the TSX output from the right panel and save it as a .tsx file, replacing your original .jsx or .js file.

Example: Simple Function

JavaScript

// JavaScript React Component
import React, { useState } from 'react';

function SearchBar({ placeholder, onSearch }) {
  const [value, setValue] = useState('');
  return (
    <input
      placeholder={placeholder}
      value={value}
      onChange={e => setValue(e.target.value)}
      onKeyDown={e => e.key === 'Enter' && onSearch(value)}
    />
  );
}

TSX

// TypeScript React Component (.tsx)
import React, { useState } from 'react';

interface SearchBarProps {
  placeholder: string;
  onSearch: (query: string) => void;
}
function SearchBar({ placeholder, onSearch }: SearchBarProps): React.ReactElement {
  const [value, setValue] = useState<string>('');
  return (
    <input
      placeholder={placeholder}
      value={value}
      onChange={(e: React.ChangeEvent<HTMLInputElement>) => setValue(e.target.value)}
      onKeyDown={(e: React.KeyboardEvent<HTMLInputElement>) => e.key === 'Enter' && onSearch(value)}
    />
  );
}

How to Convert JavaScript React Components to TSX

Migrating a JavaScript React component to TypeScript TSX means writing TypeScript interfaces for every prop, adding generic types to every useState and useRef hook, typing every event handler, and renaming the file from .js or .jsx to .tsx. For a medium-sized component with 8 props and 4 hooks, that is 25+ manual changes.

The JS to TSX converter handles every change automatically. Paste any JavaScript React component and get production-ready TypeScript TSX with interfaces, typed hooks, and event handler types — rename the file to .tsx and you are done.

Why Migrate JS React Components to TSX?

→TypeScript catches prop type mismatches before they cause runtime errors in production
→IDE autocomplete on typed props eliminates guessing component APIs from source code
→Typed hooks (useState<User | null>) prevent accessing properties on undefined values
→TypeScript is now the React community standard — most new React projects require .tsx files

What the JS to TSX Converter Handles

Prop interface generation

useState<T> generics

useRef<HTMLElement> types

useCallback parameter types

useMemo return types

Event handler typing

PropTypes removal

React.FC deprecation handling

Default props to optional types

Context type annotations

Custom hook return typing

File extension note (.tsx)

Frequently Asked Questions

How do I convert a JavaScript React component to TypeScript?

Paste your JS React component into the converter and click Convert. The AI adds TypeScript interfaces for props, types all hooks, adds event handler types, and notes the file should be renamed to .tsx. Copy and save as your-component.tsx.

What is the difference between .js, .jsx, and .tsx?

.js files are plain JavaScript. .jsx files are JavaScript with JSX (React) syntax. .tsx files are TypeScript with JSX syntax. To use TypeScript with React, your component files must use the .tsx extension.

Do I need to convert all files at once?

No. TypeScript supports gradual migration. You can convert one component at a time, keeping other files as .js or .jsx. TypeScript's allowJs option lets .ts and .js files coexist in the same project.

How do I type useState in a TypeScript React component?

TypeScript usually infers from the initial value: useState(0) infers number. For null initial values, specify the type: useState<User | null>(null). The converter adds generics automatically wherever TypeScript cannot infer the type.

What happens to React.PropTypes during conversion?

PropTypes are replaced by TypeScript interfaces — more powerful and checked at compile time instead of runtime. The PropTypes import is removed and each PropTypes definition becomes a TypeScript interface.

Can I convert a JavaScript class component to TSX?

Yes. Class components get typed state (State interface), typed props (Props interface), and typed lifecycle method return values. The converter handles Component<Props, State> generic syntax.

How do I type a function that returns JSX in TypeScript?

Use React.ReactElement as the return type: function MyComponent(): React.ReactElement { return <div />; }. For components that might return null, use React.ReactElement | null. Avoid JSX.Element — React.ReactElement is more precise.

Is the JS to TSX converter free?

Yes. Completely free, no account or login required. Unlimited conversions.

How do I handle third-party JS libraries without TypeScript types?

Install @types/library-name from npm for most popular libraries. If no @types package exists, declare the module: declare module "library-name" { export function myFunc(): void; }. The converter focuses on your component code, not third-party imports.

Should I use React.FC or explicit return types?

The React community has moved away from React.FC (it was deprecated in the @types/react v18 update for new projects). Use explicit return type annotations: function MyComponent(): React.ReactElement instead of const MyComponent: React.FC<Props>.