ES5 to ES6 Converter - Modernize JavaScript Code Online
Free online tool to convert ES5 JavaScript to modern ES6+ syntax with arrow functions, let/const, template literals, and more.
ES5 to ES6+ Converter
Modernize your JavaScript code with ES6+ features
ES5 Input
ES6+ Output
ES6+ code will appear here
Paste ES5 code in the input area
How to Convert ES5 to ES6+ - Step by Step Guide
Input Your ES5 Code
Let's modernize your legacy ES5 code to ES6+! You have several options:
Example: ES5 Code Input
Here's legacy ES5 JavaScript:
var numbers = [1, 2, 3]; var doubled = numbers.map(function(n) { return n * 2; });
Automatic Modern Syntax Conversion
The converter modernizes your code instantly! It automatically applies:
Example: Modern ES6+ Output
The same code with modern syntax:
const numbers = [1, 2, 3]; const doubled = numbers.map((n) => n * 2);
Review Modern Features
Check the modernized code with ES6+ features:
Export Modern Code
Save your modernized JavaScript:
Frequently Asked Questions
What ES6+ features does this converter add?
The converter adds arrow functions, let/const declarations, template literals, destructuring, spread operators, and other modern JavaScript features where applicable. It analyzes your ES5 code and applies appropriate ES6+ syntax.
Will converted code work in all browsers?
ES6+ features work in all modern browsers. For older browser support, use transpilation tools like Babel to convert ES6+ back to ES5. Most modern projects target recent browsers that fully support ES6+.
Why should I modernize ES5 to ES6+?
Modern ES6+ syntax is more concise, readable, and follows current best practices. It provides better variable scoping, cleaner function syntax, and improved string handling. Modernizing code makes it easier to maintain and understand.
Does conversion change code behavior?
No, the conversion preserves code functionality. Arrow functions and let/const have some scoping differences from their ES5 counterparts, but the converter applies them appropriately. Always test converted code to ensure it works as expected.
Can I convert ES6+ back to ES5?
Yes, use transpilers like Babel or our JavaScript Transpiler to convert ES6+ features back to ES5 for compatibility with older environments. This is common in production builds targeting wider browser support.
Is the ES5 to ES6 converter completely free?
Yes, totally free with no limitations on file size or usage frequency. No registration required, and you can modernize unlimited JavaScript files to ES6+ syntax.