How to Use This JSON Validator & Formatter
- Paste your JSON code into the text area above.
- Click the "VALIDATE & FORMAT" button.
- If your JSON is valid, the text area will be updated with the "pretty-printed" (indented) version.
- If your JSON is invalid, a red error message will appear below the buttons, telling you what went wrong.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write and easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999. JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.
What is a JSON Validator?
A JSON validator is a tool that checks if a given string follows the JSON format syntax. It ensures that the structure and values are correct according to the JSON specification. This is crucial for data exchange between a server and a web application, as the data must be correctly formatted to be parsed and used by the receiving application (e.g., in Python, Java, or JavaScript).
The validator catches common mistakes, saving developers significant time debugging issues related to data transfer and configuration files.
Common JSON Syntax Errors
- Trailing Commas: Adding a comma after the last element in an array or the last property in an object.
[1, 2, 3,]or{"a":1, "b":2,}are invalid. - Using Single Quotes: JSON keys and string values must be enclosed in double quotes (").
{'key': 'value'}is invalid. It must be{"key": "value"}. - Missing Commas: Forgetting to place a comma between elements in an array or properties in an object.
- Mismatched Brackets: Not closing an object with a curly brace
}or an array with a square bracket].
JSON Validator FAQ
Is this tool free?
Yes, this online JSON validator and formatter is 100% free.
Is my data safe?
Yes, your data is completely safe. All validation and formatting logic runs locally in your web browser using JavaScript. Your data is never sent or uploaded to our server.