JSON Tools
Format, compress, tree view, struct generation, and sample JSON generator.
JSON Input
📋
Enter JSON on the left to get started
📖 JSON Tools Guide
Introduction
JSON (JavaScript Object Notation) is the most popular data format in web development. This tool provides formatting, validation, compression, and code generation in one place.
Features
- Format: Beautify minified JSON with proper indentation
- Validate: Detect syntax errors with precise locations
- Compress: Remove whitespace for compact output
- Field extraction: List all key paths and their types
- Code generation: Generate structs for Go/TypeScript/Rust/Python/Java
How to Use
- Paste JSON into the editor
- Auto-formatted preview appears
- View field structure and generate code on the right
- Select target language for struct definitions
- Copy the result
Example
Minified JSON → Formatted with indentation
JSON fields → TypeScript interface or Go struct
Use Cases
- Debugging API JSON responses
- Generating type definitions from sample data
- Validating JSON syntax during development
- Editing JSON configuration files
Frequently Asked Questions
What's the difference between JSON and a JavaScript object literal?
JSON is a cross-language data interchange format, while a JavaScript object literal is JS-specific. JSON has stricter syntax: keys must be double-quoted, JavaScript types like undefined/functions/Symbols are not allowed, and trailing commas are forbidden. JSON can be parsed by any language, object literals only work in JavaScript.
Does JSON support comments?
Standard JSON does not support comments. This is an intentional design choice by JSON's creator Douglas Crockford. Editors like VS Code support JSONC (JSON with Comments), but it's not part of the standard. For configurations that need comments, consider YAML.
How do I know if a string is valid JSON?
The most reliable way is to try JSON.parse() — if it throws an exception, it's invalid. Common issues include: unquoted keys, single quotes, trailing commas, and comments. This tool validates your input in real-time and highlights errors.
Can JSON numbers lose precision?
JSON itself doesn't limit number range, but JavaScript's Number type is a 64-bit double-precision float. Safe integer range is -2^53 to 2^53 (~9 quadrillion). Numbers beyond this lose precision. Solution: use string representation for large integers, e.g. "id": "9007199254740993".
What's the difference between JSON and XML?
Both are data interchange formats. JSON is more concise: no closing tags, faster parsing, smaller payload. XML supports attributes, namespaces, and Schema validation. Today, nearly all REST APIs use JSON, while SOAP and legacy systems still use XML.
Usage Examples
User Profile
A user profile showing strings, numbers, booleans, arrays, and nested objects.
{
"name": "John Doe",
"age": 28,
"email": "john@example.com",
"active": true,
"tags": ["developer", "backend"],
"address": {
"city": "Beijing",
"district": "Haidian",
"zip": "100000"
}
}API Response
A paginated API response with data list and pagination info.
{
"code": 200,
"message": "success",
"data": {
"items": [
{ "id": 1, "title": "Article One", "views": 1234 },
{ "id": 2, "title": "Article Two", "views": 892 },
{ "id": 3, "title": "Article Three", "views": 567 }
],
"pagination": {
"page": 1,
"pageSize": 10,
"total": 56
}
}
}Config File
An application configuration file with deeply nested JSON structure.
{
"app": {
"name": "MyApp",
"version": "2.1.0",
"debug": false
},
"database": {
"host": "localhost",
"port": 5432,
"pool": {
"min": 2,
"max": 10
}
},
"logging": {
"level": "info",
"format": "json"
}
}