JSON Editor

View, edit, and format JSON data with syntax highlighting and save formatted JSON to file

JSON Editor

Valid

Format, validate, and transform JSON data

Keys22
Depth4
Size524B
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About JSON

JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write and easy for machines to parse and generate.

Key features of JSON:

  • Text-based format: JSON is language-independent and uses conventions familiar to programmers of the C-family of languages.
  • Simple structure: JSON is built on two structures - a collection of name/value pairs (object) and an ordered list of values (array).
  • Universal support: Almost all programming languages have built-in functions or libraries to parse and generate JSON.
  • Human-readable: Unlike binary formats, JSON is easy to read and edit manually.

This tool helps you work with JSON data client-side, with all processing happening in your browser for privacy and security.

JSON Format Examples

Here's an example of a JSON object representing a person:

{
  "name": "John Doe",
  "age": 30,
  "isActive": true,
  "address": {
    "street": "123 Main St",
    "city": "Anytown",
    "zipCode": "12345"
  },
  "phoneNumbers": [
    {
      "type": "home",
      "number": "555-1234"
    },
    {
      "type": "work",
      "number": "555-5678"
    }
  ]
}

Common JSON data types:

Data TypeExampleDescription
String"Hello, world!"Text enclosed in double quotes
Number42, 3.14159Integer or floating-point
Booleantrue, falseLogical true or false values
Object{ "key": "value" }Collection of key-value pairs
Array[1, 2, 3]Ordered list of values
NullnullRepresents no value

Using JSON in Different Languages

Here are examples of how to work with JSON in different programming languages:

JavaScript:


// Parse JSON string into an object
const jsonString = '{"name": "John", "age": 30}';
const obj = JSON.parse(jsonString);
console.log(obj.name); // "John"

// Convert object to JSON string
const person = { name: "Jane", age: 25 };
const json = JSON.stringify(person);
console.log(json); // '{"name":"Jane","age":25}'
                

Python:


import json

# Parse JSON string into a dictionary
json_string = '{"name": "John", "age": 30}'
data = json.loads(json_string)
print(data["name"])  # "John"

# Convert dictionary to JSON string
person = {"name": "Jane", "age": 25}
json_string = json.dumps(person)
print(json_string)  # '{"name": "Jane", "age": 25}'
                

Java:


// Using Jackson library
import com.fasterxml.jackson.databind.ObjectMapper;

// Parse JSON string into an object
String jsonString = "{\"name\": \"John\", \"age\": 30}";
ObjectMapper mapper = new ObjectMapper();
JsonNode node = mapper.readTree(jsonString);
String name = node.get("name").asText();  // "John"

// Convert object to JSON string
Map<String, Object> person = new HashMap<>();
person.put("name", "Jane");
person.put("age", 25);
String json = mapper.writeValueAsString(person);
                
100% Client-Side
No Data Upload
Instant Processing

DevToolCafe's free online JSON editor is the best JSON formatter and validator for developers. This powerful client-side JSON tool lets you view, edit, format, and validate JSON data instantly in your browser. Unlike other online JSON editors, all processing happens locally on your device — your data never leaves your computer, ensuring complete privacy and security. Whether you're debugging API responses, formatting configuration files, or validating JSON syntax, our JSON editor online provides a fast, secure, and feature-rich experience.

What is a JSON Editor?

A JSON Editor is a specialized tool designed to help developers work with JSON (JavaScript Object Notation) data. JSON is the most widely used data interchange format on the web, used in REST APIs, configuration files, and data storage. Our online JSON formatter and validator provides syntax highlighting, real-time error detection, tree view navigation, and format conversion capabilities. It's an essential tool for web developers, backend engineers, and anyone working with JSON data structures.

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Why Use Our JSON Editor?

100% Private & Secure

All JSON processing happens client-side in your browser. Your sensitive data never leaves your device — no server uploads, no data collection, complete privacy.

Instant Formatting & Validation

Format messy JSON with one click. Real-time syntax validation catches errors as you type, with clear error messages pointing to exact line numbers.

Tree View Navigation

Visualize complex nested JSON structures with our interactive tree view. Expand, collapse, and navigate large JSON files with ease.

Multiple Export Formats

Convert JSON to YAML, XML, or download as a formatted file. Perfect for configuration management and data transformation workflows.

How to Use the JSON Editor

1

Paste or Upload Your JSON

Copy your JSON data and paste it into the editor, or click the upload button to load a JSON file from your computer.

2

Format and Validate

Click the 'Format' button to beautify your JSON with proper indentation. The editor automatically validates syntax and highlights any errors.

3

Edit and Navigate

Make changes directly in the editor with syntax highlighting. Use the tree view to navigate complex nested structures.

4

Export or Copy

Download your formatted JSON as a file, copy to clipboard, or convert to YAML/XML format for your specific needs.

Frequently Asked Questions