JavaScript Validator

Validate JavaScript syntax and detect errors

Input

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Validation Results

Validation results will appear here

Paste JavaScript in the input area to validate

How to Validate JavaScript - Step by Step Guide

Step 1

Input Your JavaScript Code

Let's get your JavaScript code into the validator! You have several convenient options:

Paste directly: Copy your JavaScript code and paste it into the input editor
Upload a file: Click "Upload" to select a .js or .txt file from your computer
Try the sample: Click "Sample" to load example code with common errors

Example: JavaScript Code with Potential Errors

Here's sample JavaScript code that needs validation:

function calculateTotal(items) {
  let total = 0;
  for (let i = 0; i < items.length; i++) {
    total += items[i].price;
  }
  return total;
}
Step 2

Automatic Syntax Validation

The validator analyzes your code instantly! As soon as you input JavaScript, the validator automatically:

Checks syntax: Validates JavaScript syntax and identifies parsing errors
Detects errors: Finds missing brackets, unclosed strings, and syntax issues
Shows line numbers: Pinpoints exact location of errors for quick fixing

Example: Validation Results

The validator provides detailed feedback:

Valid JavaScript

No syntax errors found. Your code is valid!

Step 3

Review Detailed Error Reports

Get comprehensive error analysis! The validator provides clear, actionable feedback:

Error messages: Clear descriptions of what went wrong
Line and column numbers: Exact location of each error
Suggestions: Helpful hints on how to fix common issues
Step 4

Fix and Re-validate

Make corrections and validate again! The validator helps you iterate quickly:

Real-time validation: See results as you type and fix errors
Copy valid code: Once validated, copy your code for use
Download validated code: Save your validated JavaScript as a file

Frequently Asked Questions

What types of JavaScript errors does this validator detect?

The validator detects syntax errors including missing brackets, unclosed strings, incorrect operator usage, missing semicolons, and invalid function declarations. It checks for basic JavaScript parsing errors to ensure your code will run without syntax issues.

Does the validator check for logical errors or just syntax?

This validator primarily checks for syntax errors and basic parsing issues. It ensures your code is syntactically correct but doesn't analyze logical errors, runtime issues, or code quality. For code formatting, use our JavaScript Beautifier.

Can I validate ES6+ and modern JavaScript syntax?

Yes! The validator supports modern JavaScript syntax including ES6+, arrow functions, template literals, async/await, destructuring, and other modern features. It validates code based on standard JavaScript specifications.

Can I validate large JavaScript files?

Absolutely! The validator efficiently handles large JavaScript files. Upload or paste code of any size, and the validator will analyze it quickly, providing detailed error reports with line numbers for easy debugging.

Is my JavaScript code stored or shared when I validate it?

No, absolutely not. All validation happens entirely in your browser. Your code never leaves your computer, ensuring complete privacy and security. We don't store, log, or transmit any code you validate.

Is the JavaScript validator completely free?

Yes, totally free with no limitations on file size, usage frequency, or features. No registration required, and you can validate unlimited JavaScript files with detailed error reporting and syntax highlighting.