JSON Viewer & Formatter
Format, validate, and visualise JSON data instantly. Paste raw or minified JSON and get a clean, colour-coded, collapsible tree view. Ideal for debugging API responses, inspecting configuration files, and sharing readable data structures with your team. All processing happens entirely in your browser — your data never leaves your device.
The parsed JSON will appear here
What is JSON?
JSON (JavaScript Object Notation) is a lightweight, language-independent data interchange format. It is built on two universal data structures: objects (key–value pairs) and arrays (ordered lists). JSON is the backbone of REST APIs, configuration files, and NoSQL databases like MongoDB and Firebase.
Originally derived from JavaScript, JSON is now natively supported by virtually every programming language — Python, Go, Rust, PHP, Java, C#, and more.
JSON Syntax Rules
- Data in key/value pairs:
"name": "value" - Keys must be strings in double quotes
- Values: string, number, boolean, null, array, or object
- Arrays use
[ ], objects use{ } - No trailing commas — a common source of parse errors
- No comments are allowed in standard JSON
Tips & Tricks
- Use Format to beautify minified JSON at one click
- Collapse and expand nested objects with the arrow icons
- Copy formatted output to clipboard instantly
- Paste directly from Postman, cURL, or browser DevTools
- Your data never leaves the browser
Common JSON Use Cases
API Debugging
Inspect REST API responses from Postman, cURL, or browser DevTools.
Config Files
Read and edit configuration files like package.json or tsconfig.json.
Data Exchange
Share structured data between services, languages, and platforms.
NoSQL Databases
View MongoDB, DynamoDB, or Firestore documents in a readable format.