Free JSON Validator Online

JSON Validator Online for Developers

Use this free JSON Validator Online to check whether a JSON object or array follows valid JSON syntax. The tool works as a JSON syntax checker and formatter: paste a JSON payload, validate it, review a readable error when the syntax is invalid, or format valid JSON with your preferred indentation.

It is useful when working with API responses, configuration files, web applications, JavaScript projects, and other developer workflows. Whether you are checking JSON from a project in the US, UK, India, or elsewhere, the same standard JSON syntax rules apply.

How to Use the JSON Validator

1. Paste or type your JSON into the input box.
2. Choose 2 spaces, 4 spaces, or tabs for formatted output.
3. Select Validate JSON to check the JSON syntax.
4. If the JSON is valid, review the formatted result, copy it, or download the `.json` file.

What This JSON Syntax Checker Checks

The validator uses your browser's built-in JSON parser to check standard JSON syntax. It handles objects, arrays, strings, numbers, booleans, null values, nested structures, escaped characters, Unicode text, and common API-style payloads. When JSON is invalid, the tool shows a syntax error and, when the browser provides a character position, reports the related line and column.

Common JSON Errors

Typical problems include a missing comma between properties, an unclosed object or array, unquoted property names, single quotes instead of JSON double quotes, an extra trailing comma, or invalid values such as True and False. Correcting the reported syntax and validating again should produce a formatted JSON result.

Privacy and Browser Processing

This validator performs JSON parsing and formatting in your browser. The page's validation code does not send the JSON input to a remote validation service. For your own safety, avoid pasting passwords, private keys, payment information, access tokens, or other confidential data into any online tool.

Frequently Asked Questions