Paste your JavaScript Code:
Actions
Syntax Checker
Click 'Validate Syntax' to parse code.
Powered by Esprima: Performs full AST parsing to find real syntax errors.
Advanced JavaScript Debugger & Formatter
JavaScript is a logic-heavy language where a single typo can crash an application. Our tool isn't just a formatter—it includes a powerful Syntax Validator powered by the Esprima parser.
Capabilities
- AST Parsing: Unlike regex-based checkers, we build an Abstract Syntax Tree to understand your code's logic and catch invalid structures.
- Safe Minification: Compresses code while preserving functionality. Great for small scripts and bookmarklets.
- Auto-Formatting: Turns "spaghetti code" into clean, readable functions with consistent indentation.
JavaScript FAQ
What errors can this tool find?
It catches syntax errors like missing parentheses ), unexpected tokens, invalid variable declarations (var 123 = x), and unclosed string literals.
Does it support ES6/ESNext?
Yes, standard ES6 syntax like arrow functions () => {} and const/let are supported.
Is my code saved?
No. All processing happens locally in your browser or temporarily in memory. We do not store any user code.