Free JSON Formatter & Validator
Format and beautify JSON with readable indentation, validate JSON syntax, or minify JSON by removing unnecessary whitespace. This free online JSON tool processes your input locally in your browser.
Paste JSON or load the example. Your input is processed locally in this browser.
What is JSON?
JSON (JavaScript Object Notation) is a text format used to store and exchange structured data. It commonly represents objects, arrays, strings, numbers, booleans, and null values.
How to format, validate and minify JSON
- Paste your JSON into the input box.
- Select an indentation size if you want to format it.
- Choose Format JSON, Validate JSON, or Minify JSON.
- Use Copy Result to copy the processed JSON.
JSON formatting and validation guide
Use Format JSON to add line breaks and indentation, making nested objects and arrays easier to inspect. Choose 2 spaces, 4 spaces or tabs for indentation. Use Validate JSON to check syntax without changing the input, or Minify JSON to remove formatting whitespace while keeping the JSON data structure.
Frequently asked questions
What does a JSON validator check?
It checks whether the input follows JSON syntax rules. It does not verify whether the data is factually correct or matches a particular application's requirements.
What is the difference between formatting and minifying JSON?
Formatting adds whitespace and indentation to improve readability. Minifying removes unnecessary whitespace to create a more compact JSON string. Both preserve the represented JSON data.
Does this tool support JSON arrays and nested objects?
Yes. It uses the browser’s built-in JSON parser and supports valid JSON values, including objects, arrays, strings, numbers, booleans and null.
Why is my JSON invalid?
Common causes include missing quotation marks around property names, trailing commas, missing brackets, or single quotes where JSON requires double quotes.
Is my JSON uploaded?
No. This tool processes JSON in your browser and does not send the input to a NinaTools server. Avoid pasting sensitive information into any website unless you trust the page and your device.