Three simple steps
How to use this tool?
This free online converter translates JavaScript source code into TypeScript in three simple steps.
- Step 1
Add your JavaScript code
Type, paste, or upload the JavaScript code you want to translate.
- Step 2
Convert the code
Click Convert to translate the source code into TypeScript.
- Step 3
Review the result
Review, copy, or download the resulting TypeScript code from the output editor.
See it in action
Examples of JavaScript to TypeScript conversion
These examples show JavaScript source code and the corresponding TypeScript translation. Generated results can vary as AI models are updated.
Example 1
Is String Palindrome
Program that checks if a string is a palindrome or not.
JavaScript code
TypeScript code
Example 2
Even or Odd
A well commented function to check if a number if odd or even.
JavaScript code
TypeScript code
Language comparison
Key differences between JavaScript and TypeScript
| Characteristic | JavaScript | TypeScript |
|---|---|---|
| Syntax | JavaScript has a more flexible and forgiving syntax compared to TypeScript. | TypeScript has a stricter syntax compared to JavaScript, with the addition of type annotations. |
| Paradigm | JavaScript is a multi-paradigm language that supports both object-oriented and functional programming. | TypeScript is a superset of JavaScript and supports the same paradigms as JavaScript, with the addition of static typing. |
| Typing | JavaScript is a dynamically typed language, which means that types are determined at runtime. | TypeScript is a statically typed language, which means that types are determined at compile time. |
| Performance | JavaScript is generally slower than TypeScript due to its dynamic typing and lack of type checking. | TypeScript is generally faster than JavaScript due to its static typing and type checking. |
| Libraries and frameworks | JavaScript has a vast collection of libraries and frameworks, including React, Angular, and Vue. | TypeScript can use the same libraries and frameworks as JavaScript, with the added benefit of type checking and better IDE support. |
| Community and support | JavaScript has a large and active community with plenty of resources and support available. | TypeScript has a growing community with increasing support and resources available. |
| Learning curve | JavaScript has a relatively low learning curve due to its forgiving syntax and dynamic typing. | TypeScript has a steeper learning curve compared to JavaScript due to its stricter syntax and static typing. |
Common questions
Frequently Asked Questions
How do I convert JavaScript to TypeScript?
Paste your JavaScript code into the input box, confirm the languages are set to JavaScript and TypeScript, and click Convert. CodeConvert AI analyzes your JavaScript code and generates equivalent TypeScript code in seconds, preserving the original logic and structure.
What are the main differences between JavaScript and TypeScript?
JavaScript and TypeScript differ in syntax, type system, standard libraries, and common idioms, so copying code line for line usually will not compile. The converter maps each JavaScript construct to its closest TypeScript equivalent. See the comparison table below for the key differences between JavaScript and TypeScript.
Is the converted TypeScript code accurate?
The AI produces high-quality TypeScript code that preserves the behavior of your original JavaScript code and follows TypeScript conventions. It handles common patterns, data structures, and idioms for both JavaScript and TypeScript. For large or performance-critical code, review and test the TypeScript output before using it in production.
Can I convert an entire JavaScript project to TypeScript?
You can convert JavaScript files one at a time by pasting each file's code. For a full migration, convert each file and then review how classes, dependencies, and project structure map from JavaScript to TypeScript. Signing in for free raises the input limit to 25,000 characters per conversion for larger files.
Can I convert TypeScript back to JavaScript?
Yes. CodeConvert AI converts in both directions, so you can convert TypeScript to JavaScript just as easily using our TypeScript to JavaScript converter. Try the TypeScript to JavaScript Converter
Is the JavaScript to TypeScript converter free, and do I need to install anything?
Yes, it is free and runs in your browser with nothing to install and no IDE extension required. You can convert JavaScript to TypeScript without an account for up to 5 conversions per day. Sign in for free for higher limits.
What are the benefits of signing in?
Signing in unlocks CodeConvert AI's Pro converter with more powerful AI models, a built-in chat assistant, code execution, saved conversion history, and personal notes. Every free account includes 5 credits and supports up to 25,000 characters of input per conversion, with no credit card required.
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