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Hazuu Tools

JSON Validator

Validate your JSON syntax instantly and pinpoint errors with line and column numbers.

JSON Input
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About JSON Validator

JSON is the standard format for data exchange across APIs, configuration files, and web applications. A single misplaced comma, missing bracket, or trailing comma can cause parsing failures that are difficult to locate in large JSON documents.

Our JSON Validator checks your JSON syntax instantly and pinpoints errors with line and column numbers. It can also auto-format valid JSON for better readability. All validation runs locally in your browser — your data never leaves your machine.

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How to Use

01

Paste Your JSON

Copy your JSON data and paste it into the editor, or upload a .json file.

02

Validate

Click "Validate" to check syntax. Errors are shown with line and column numbers.

03

Fix & Format

Fix any errors, then click "Format" to auto-indent your valid JSON for readability.

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Frequently Asked Questions

What is a JSON Validator? expand_more
A JSON Validator checks whether a string of text is valid JSON according to the JSON specification (RFC 8259). It identifies syntax errors like missing commas, unmatched brackets, trailing commas, and invalid values, and reports the exact location of each error.
What common JSON errors does this catch? expand_more
The validator catches missing or extra commas, unmatched braces or brackets, single quotes instead of double quotes, trailing commas in arrays or objects, unquoted keys, and invalid values like undefined or NaN.
Is my JSON data secure? expand_more
Yes. All validation runs entirely in your browser using native JSON.parse. Your data never leaves your machine and is not sent to any external server.
Can this tool also format my JSON? expand_more
Yes. Click the "Format" button to both validate and auto-format your JSON with consistent 2-space indentation, making it easier to read and debug.