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JavaScript Validator
Check JavaScript syntax without running the script. For execution, use JS Runner.
JavaScript55 chars
Validation Result27 chars
About JavaScript Validator
Check JavaScript syntax without running the script. Parse errors (missing braces, unexpected tokens) show immediately. Runtime behavior needs JS Runner — this page never executes your code.
Common Use Cases
- Syntax check before review
- Validate a snippet without a sandbox
- Catch typos in pasted JS
- Separate parse errors from runtime errors
Tips
- Parsed with the browser, never invoked
- Use JS Runner for console output
- TypeScript needs stripping before this parser
Frequently Asked Questions
Does this JavaScript validator run my code?
No. It parses the snippet with the browser Function constructor for syntax only. The body is never invoked. Use JS Runner if you need execution.
What errors will it catch?
Parse errors: missing braces, unexpected tokens, invalid syntax. It will not catch runtime errors, type errors, or logic bugs.
How is this different from a JavaScript sandbox?
A validator checks syntax. A sandbox (JS Runner) executes the script in an iframe. Use this page to check a snippet; use JS Runner to see console output.
Is my JavaScript uploaded?
No. Validation is client-side.