Validate JavaScript

Parse JavaScript source for ECMAScript syntax errors and report their location.

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ToolJavaScript Validator

Input

Output

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How it works

The source is parsed with Acorn using current ECMAScript grammar in module mode with import, export, top-level await, return, and hashbang options. A successful parse is valid syntax; failures return the parser message and line and column.

Current ECMAScript keeps syntax support up to date.
Module mode covers modern import and export files.

Worked example

Valid JavaScript

Validate syntactically correct JavaScript code

Input

											const greet = (name) => `Hello, ${name}!`;
console.log(greet('World'));

Output

												Valid JavaScript syntax

When to use this

CI gates, editors, and bundling pipelines parse JavaScript before execution.

Edge cases

Code can parse while browser globals remain undefined at runtime.
A missing brace reports a syntax error without executing code.
TypeScript interfaces are rejected because they are not ECMAScript syntax.

References

ECMAScript specification