JSON Formatter & Validator

Paste your JSON to instantly format, minify, or validate it. Syntax highlighted output with error detection.

{ } JSON Tool

Input
Paste JSON to validate
Output

What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format. It is easy for humans to read and write, and easy for machines to parse and generate. JSON is built on two structures: objects (collections of key-value pairs enclosed in curly braces) and arrays (ordered lists of values enclosed in square brackets).

JSON has become the de facto standard for data exchange on the web. REST APIs, configuration files, NoSQL databases (MongoDB, CouchDB), and frontend/backend communication all use JSON extensively.

Why Formatting Matters

Minified JSON is compact and efficient for data transfer, but nearly impossible to read. Formatted (prettified) JSON adds indentation and line breaks, making it easy to understand the structure at a glance. This is essential for debugging API responses, reviewing config files, and collaborating with other developers.

Common JSON Errors

Trailing commas: JSON does not allow a comma after the last item in an object or array (unlike JavaScript).
Single quotes: JSON requires double quotes for strings and keys. Single quotes are not valid.
Unquoted keys: All keys must be enclosed in double quotes.
Comments: Standard JSON does not support comments (// or /* */).

JSON vs XML

JSON is lighter, more readable, and faster to parse. It uses key-value pairs and arrays. XML uses nested tags and is more verbose, but supports attributes, namespaces, and schemas. JSON is the standard for modern web APIs. XML is still used in legacy SOAP services, RSS feeds, SVG graphics, and enterprise systems.

Frequently Asked Questions

How do I format JSON online?
Paste your JSON into this tool and click Format. It will add 2-space indentation and line breaks for readability, plus syntax highlighting.
How do I validate JSON?
Paste your JSON above. The tool instantly validates it, showing a green Valid JSON indicator or a red error message with the exact error position.
What is JSON used for?
REST APIs, configuration files, NoSQL databases, frontend-backend communication, and data storage. It's the standard data interchange format for modern web development.
How do I minify JSON?
Paste your JSON and click Minify. It removes all whitespace, producing the most compact representation for efficient data transfer.
What is the difference between JSON and XML?
JSON is lighter and easier to read, using key-value pairs. XML uses nested tags and is more verbose. JSON dominates modern APIs; XML remains in legacy systems, SOAP, and document formats.