title: JSON Editor description: Edit, format, validate, and minify JSON data online. Real-time validation with error highlighting and file upload/download support
What is a JSON Editor?
A JSON Editor is a tool for creating, editing, and validating JSON (JavaScript Object Notation) data. Our editor provides real-time validation, formatting, minification, and file management capabilities.
Features
✅ Real-Time Validation
See instantly whether your JSON is valid or contains errors.
📐 Format & Beautify
Convert minified JSON into readable, properly indented code.
🗜️ Minify
Remove whitespace to create the smallest possible file size.
📤 Upload & Download
Import JSON files and export your edited data.
📊 Statistics
View JSON type, key count, and file size at a glance.
JSON Syntax Rules
Valid JSON Values
| Type | Example |
|---|---|
| String | "hello world" |
| Number | 42, 3.14, -17 |
| Boolean | true, false |
| Null | null |
| Object | {"key": "value"} |
| Array | [1, 2, 3] |
Common Syntax Errors
| Error | Wrong | Correct |
|---|---|---|
| Single quotes | 'value' | "value" |
| Trailing comma | [1, 2,] | [1, 2] |
| Unquoted key | {key: 1} | {"key": 1} |
| Undefined | undefined | null |
Example JSON Structure
{
"name": "John Doe",
"age": 30,
"email": "[email protected]",
"address": {
"street": "123 Main St",
"city": "New York",
"country": "USA"
},
"hobbies": ["reading", "gaming", "traveling"],
"isActive": true,
"metadata": null
}
JSON vs JavaScript Objects
| Aspect | JSON | JavaScript |
|---|---|---|
| Keys | Must be quoted | Optional quotes |
| Strings | Double quotes only | Single or double |
| Comments | Not allowed | Allowed |
| Trailing commas | Not allowed | Allowed |
| Functions | Not allowed | Allowed |
Frequently Asked Questions
What does "Unexpected token" mean?
This error indicates a syntax issue, often a missing quote, bracket, or comma.
Can I add comments to JSON?
No, standard JSON doesn't support comments. Consider using JSONC (JSON with Comments) extensions.
Why won't my JSON validate?
Common issues include: single quotes instead of double, trailing commas, missing brackets, or unquoted keys.
What's the maximum JSON size?
There's no official limit, but browsers typically handle up to 500MB. Our editor works best with files under 10MB.
How do I format minified JSON?
Paste your minified JSON and click the "Format" button to add proper indentation.
Best Practices
- Always validate — Check syntax before using in applications
- Use descriptive keys —
"firstName"instead of"fn" - Be consistent — Use camelCase or snake_case, not both
- Nest logically — Group related data in objects
- Keep it flat — Avoid deeply nested structures when possible
Use Cases
API Development
Edit and validate API request/response bodies.
Configuration Files
Create and modify config files for applications.
Data Migration
Transform and clean data between systems.
Debugging
Identify and fix JSON syntax errors.
Documentation
Format JSON examples for documentation.
Keyboard Shortcuts
| Action | Shortcut |
|---|---|
| Format JSON | Ctrl/Cmd + Shift + F |
| Copy all | Ctrl/Cmd + A, Ctrl/Cmd + C |
| Paste | Ctrl/Cmd + V |