What is a JSON viewer?

A JSON viewer is a tool that takes raw or minified JSON text and displays it in a formatted, colour-coded, and collapsible tree structure. It makes it easy to read, debug, and share JSON data without manually indenting it.

How do I validate JSON?

Paste your JSON into the editor and click Format or Validate. If the JSON is invalid, the tool highlights the error line and shows a description — such as a missing comma, mismatched bracket, or unquoted key.

Is my data safe when using DailyUtil JSON Viewer?

Yes. All JSON parsing and formatting happens entirely in your browser using JavaScript. Your data is never sent to any server, stored in a database, or logged. Safe for sensitive API responses or internal data.

What is the difference between JSON and XML?

JSON uses a lightweight key-value and array syntax — easy for both humans and machines to read. XML uses verbose tag-based structure supporting namespaces and attributes. JSON is standard for REST APIs; XML is still common in SOAP, RSS, and enterprise systems.

Can I use this tool for large JSON files?

Yes. The viewer handles JSON of any size. For very large files (MB+), collapsing top-level objects helps navigate quickly. Use the fullscreen button for maximum workspace.

What JSON value types are supported?

All standard JSON types: strings, numbers, booleans (true/false), null, objects ({}), and arrays ([]). The viewer colour-codes each type for fast visual scanning.

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.

Input JSON

0 characters

Parsed Result

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.

Frequently Asked Questions

Why JSON Formatting Matters for Modern Development

JSON (JavaScript Object Notation) has become the universal language of data exchange on the web. Every REST API, every configuration file, and every NoSQL database speaks JSON. Yet working with raw or minified JSON — stripped of whitespace and indentation for transmission efficiency — is nearly impossible without a formatting tool. A JSON viewer transforms dense, single-line payloads into a clean, colour-coded, hierarchically indented structure that developers can read, debug, and share in seconds. Whether you are inspecting a 200-line API response from Postman, troubleshooting a misconfigured tsconfig.json, or reviewing a MongoDB document, proper formatting is the first step toward understanding the data.

Common JSON Debugging Workflows

The most frequent use of a JSON viewer is debugging API responses. A typical workflow starts with copying a response from browser DevTools, cURL, or an API client, pasting it into the viewer, and immediately spotting structural issues — missing commas, mismatched brackets, or unexpected null values. Our viewer validates the JSON on paste, highlights syntax errors with precise line numbers, and lets you collapse and expand nested objects to focus on the section that matters. For large payloads, the tree view provides a navigable outline of the entire document. This is especially valuable when working with deeply nested structures common in GraphQL responses, Elasticsearch queries, and cloud infrastructure configurations like AWS CloudFormation or Terraform state files.

JSON in the Developer Ecosystem

Beyond API debugging, JSON is the backbone of modern developer tooling. Package managers use package.json, TypeScript uses tsconfig.json, ESLint uses .eslintrc.json, and VS Code stores all its settings in JSON. Understanding JSON structure and being able to quickly validate it saves hours of debugging configuration errors. DailyUtil offers a complete suite of data format tools: use the YAML Viewer for Kubernetes and Docker Compose files, the XML Viewer for SOAP and RSS feeds, the JWT Decoder to inspect Base64-encoded JSON payloads in authentication tokens, and the Base64 Tool for encoding and decoding data. For API testing, try the API Request Builder. Explore all tools on the homepage or learn more about DailyUtil.