JavaScript Validator - Check JS Syntax Online
Validate your JavaScript code instantly with our free online JS Validator. Detect syntax errors, undefined variables, and potential runtime issues before they break your application.
Why Validate Your JavaScript?
- Prevent Runtime Errors: Catch bugs before users encounter them
- Faster Debugging: Identify exact line numbers with errors
- Code Quality: Maintain high standards across your codebase
- ES6+ Support: Validates modern JavaScript syntax
Common Use Cases
🔍 Pre-Commit Check
Validate code before pushing to repositories.
🐛 Quick Debugging
Find syntax errors when your code won't run.
📚 Learning JavaScript
Understand syntax rules as you learn to code.
📋 Code Review
Quickly validate snippets during pull requests.
How to Use This Tool
- Paste Your JavaScript: Enter the JS code you want to validate.
- Click "Validate JavaScript": Our tool parses and checks your code.
- Review Results: See errors with line numbers and fix them.
💡 Tip: This validator checks syntax only. For style and best practices, use ESLint alongside this tool.
JavaScript Validator Tool
Results will appear here after validation...
What This Validator Checks
- Syntax Errors: Missing parentheses, brackets, or semicolons
- Parse Errors: Invalid JavaScript that can't be interpreted
- Reserved Words: Using keywords as variable names
- String Errors: Unterminated strings or template literals
- Function Syntax: Arrow functions, async/await, destructuring
- ES6+ Features: Classes, modules, spread operators
Common JavaScript Errors
Unexpected token- Missing bracket or typo in codeUnterminated string literal- Missing closing quoteUnexpected identifier- Missing operator or commaMissing } in compound statement- Unclosed block
ECMAScript Support
This validator supports modern JavaScript (ES6+) including arrow functions, classes, template literals, destructuring, async/await, and more.
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