JSON Formatter & Validator
Prettify, minify, and validate JSON directly in your browser, with clear syntax feedback and copy-ready generated output.
Input
Output
Generated JSON
No generated output yet. Prettify or minify valid JSON to create output.
How it works
JSON (JavaScript Object Notation) is a text format for representing values such as objects, arrays, strings, numbers, booleans, and null. It is widely used in APIs, configuration files, and data exchange.
Formatting and minification
Prettifying parses valid JSON and serializes it with two-space indentation, making nested data easier to read. Minifying parses the same data and serializes it without unnecessary whitespace, creating a more compact representation.
Validation and common errors
Validation uses the browser's standard JSON parser and does not rewrite your input. Trailing commas, comments, unquoted property names, single quotes, and unmatched brackets are invalid. Although JSON resembles a JavaScript object literal, it follows a smaller and stricter syntax.
The tool never evaluates JSON as JavaScript. Each action runs only when you select it, and invalid input is reported rather than repaired silently.
Example
Illustrative example, separate from your generated output:
Compact JSON
{"name":"Utilities Haven","active":true}Prettified result
{
"name": "Utilities Haven",
"active": true
}Frequently asked questions
What is JSON formatting?
JSON formatting adds consistent indentation and line breaks to valid JSON so its structure is easier to scan, review, and debug.
What is the difference between prettifying and minifying JSON?
Prettifying adds whitespace for readability. Minifying removes unnecessary whitespace to create a compact representation. Both operations parse the input first, so malformed JSON does not produce output.
Why is my JSON invalid?
Common causes include trailing commas, missing double quotation marks around property names, mismatched brackets, JavaScript comments, and single-quoted strings. JSON syntax is stricter than JavaScript object-literal syntax.
Is my JSON uploaded to a server?
No. Formatting, minification, and validation run locally in your browser. The input and generated output are kept only in the page's in-memory state.
Does formatting JSON change its values?
The tool uses standard JSON parsing and serialization, which preserves the parsed data but does not preserve original whitespace. Reserialization can also change numeric representation or object-key ordering in some cases, so it should not be treated as byte-for-byte preservation.