JSON Formatter

Format, validate and compress JSON data

Operations

Tools

📖 User Guide

Free online JSON formatter tool - Validate, beautify, compress JSON data

⚡ Quick Start

Three steps to process JSON data:

1
Paste JSON

Paste your JSON data in left input box

2
Select Operation

Click format, compress or validate button

3
View Result

Processed JSON displays right, click copy

🔧 Basic Operations

Format (Format)
  • Function: Expand compressed JSON with readable format including indentation and line breaks
  • Use: Viewing and editing JSON increases readability
  • Feature: Auto-indent and align, convenient for manual reading
  • Example:
    Input: {"name":"John","age":30}
    Output:
    {
      "name": "John",
      "age": 30
    }
Compress (Minify)
  • Function: Remove unnecessary spaces, line breaks and indentation, compress JSON size
  • Use: Reduce data volume, speed up network transmission
  • Applicable Scenarios: API requests, database storage, embedded environments
  • Example:
    Input: { "name": "John", "age": 30 }
    Output: {"name":"John","age":30}
Validate (Validate)
  • Function: Check if JSON syntax is correct
  • Error Prompt: Shows error location and type
  • Common Errors:
    • Missing or extra commas
    • Missing quotes
    • Unmatched brackets/braces
    • Invalid characters or escape
  • Result: Valid shows "Valid JSON", invalid shows error message

⭐ Advanced Tools

Sort (Sort)
  • Function: Sort JSON keys alphabetically
  • Use: Standardize JSON structure, easy comparison and version control
  • Effect: Only sorts keys, doesn't change values
  • 💡 Useful when comparing two JSONs, easier to find differences after sorting
Escape (Escape)
  • Function: Convert JSON to escaped string (suitable for embedding in code)
  • Use: Use as string in code
  • Effect: Special characters escaped (like " becomes \")
  • 💡 Usually used to hardcode JSON data in code
Unescape (Unescape)
  • Function: Convert escaped string back to readable JSON
  • Use: Read JSON stored in escaped form
  • Reverse Process: Opposite to escape

📚 JSON Basics

JSON Data Types
  • String: Must be enclosed in double quotes "", like "name"
  • Number: Integer or decimal, like 42 or 3.14
  • Boolean: true or false (lowercase)
  • null: Represents empty value
  • Array: [ 1, 2, 3 ], separated by commas with square brackets
  • Object: { "key": "value" }, represented with curly braces
Common Errors
  • ❌ Keys without quotes: { name: "John" }
  • ✅ Correct: { "name": "John" }
  • ❌ Strings with single quotes: { 'name': 'John' }
  • ✅ Correct: { "name": "John" }
  • ❌ Trailing comma in array: [ 1, 2, 3, ]
  • ✅ Correct: [ 1, 2, 3 ]

❓ Frequently Asked Questions

Q: Difference between JSON and JavaScript object?

A: JSON is standard data format, all keys must be strings (in double quotes). JavaScript objects are more flexible.

Q: Why does my JSON fail validation?

A: Common reasons: (1) Keys without quotes (2) Single quotes for strings (3) Missing or extra commas (4) Unmatched brackets

Q: Can I edit formatted JSON?

A: Yes. After formatting, edit in right box, then perform other operations. Use "Swap" to quickly exchange box contents.

Q: Why did key order change after sorting?

A: Sort function reorders all keys alphabetically. If you don't need order changed, don't click sort.

Q: Can JSON include Chinese?

A: Completely possible. Place Chinese directly in strings, no transcoding needed, formatting preserves Chinese.

📖 Usage Examples

API Response

Paste compressed JSON from API

Click "Format" to beautify

View structure and data

Data Optimization

Perfect formatted JSON

Click "Compress" to reduce size

Use for network transmission

Error Check

Copy suspicious JSON data

Click "Validate" to check syntax

Fix based on errors

Version Compare

Format two JSON versions

Click "Sort" to standardize

Easy to compare differences

💡 Usage Tips

  • Validate before processing: Use validate before processing JSON to check syntax
  • Keep original backup: Copy backup before important JSON operations
  • Use swap function: Quickly compare original and processed JSON
  • Combine with sort: After sorting, easier to find specific keys in large JSON
  • Escape for embedding: Only use escape when embedding JSON in code
  • Completely local processing: All operations in browser, sensitive data won't upload