📋 Format and Validate JSON
JSON (JavaScript Object Notation) is the most common data format for APIs, configuration files, and data exchange. This tool helps you format messy JSON into readable, properly indented code, validate syntax errors, and minify JSON for production use.
Whether you're debugging API responses, editing config files, or preparing JSON for deployment, this formatter makes JSON data easy to read and ensures it's syntactically correct before use.
🎯 How to Use the JSON Formatter
- Paste your JSON into the input area (can be minified or formatted).
- Click "Format" to beautify with proper indentation and line breaks.
- Click "Minify" to remove all whitespace for compact output.
- View validation errors if your JSON has syntax issues.
- Copy the result using the copy button.
- Choose indentation (2 or 4 spaces) for your preferred style.
🎯 Common Use Cases
🔌 API Response Debugging
Paste minified API responses to see structured, readable data. Identify nested objects, arrays, and values instantly. Debug response structure and find data you need.
⚙️ Config File Editing
Format package.json, tsconfig.json, or any JSON configuration file for better readability before committing. Ensure your config is valid before deployment.
✅ JSON Validation
Check if your JSON is syntactically valid before deploying. Get clear error messages pointing to syntax issues like missing commas, unquoted keys, or trailing commas.
📦 Production Minification
Remove whitespace and formatting to reduce file size for production environments. Faster data transmission and smaller bundle sizes for web applications.
🔍 Data Analysis
Format exported data from databases or APIs to analyze structure. Find patterns, identify missing fields, or understand complex nested data hierarchies.
📚 Documentation & Examples
Create readable JSON examples for documentation, tutorials, or code samples. Well-formatted JSON is easier for developers to understand and copy.
💡 Common JSON Syntax Errors
Missing Comma
Properties must be separated by commas. Missing commas cause "Unexpected token" errors.
// Wrong
{ "a": 1 "b": 2 }
// Right
{ "a": 1, "b": 2 } Trailing Comma
JSON doesn't allow trailing commas after the last property or array item.
// Wrong
{ "a": 1, "b": 2, }
// Right
{ "a": 1, "b": 2 } Single Quotes
JSON requires double quotes for strings and keys. Single quotes are not valid.
// Wrong
{ 'name': 'value' }
// Right
{ "name": "value" } Unquoted Keys
All object keys must be enclosed in double quotes, unlike JavaScript objects.
// Wrong
{ name: "value" }
// Right
{ "name": "value" } 🔒 Privacy & Security
All JSON formatting and validation happens entirely in your browser. Your data never leaves your device - no server uploads, no tracking, 100% private. This is especially important when working with sensitive API responses, config files containing credentials, or proprietary data structures. ToolZone itself does not track, save, or transmit any of your data.
❓ Frequently Asked Questions
What does "Format JSON" do? ▼
It parses your JSON and outputs it with proper indentation (2 or 4 spaces) making nested structures easy to read. This beautifies minified or compressed JSON into human-readable format.
How do I fix "Unexpected token" errors? ▼
Common causes: missing commas between properties, trailing commas (not allowed in JSON), unquoted keys, or single quotes instead of double quotes. JSON requires double quotes for strings and keys.
Can I use this for large JSON files? ▼
Yes, but very large files (>10MB) may be slow in the browser. For massive files, consider using command-line tools. This tool works best for typical API responses and config files.
What's the difference between Format and Minify? ▼
Format adds indentation and whitespace for readability. Minify removes all unnecessary whitespace to reduce file size - ideal for production deployment where file size matters.
Does this work with JSON5 or relaxed JSON? ▼
No, this tool validates strict JSON (RFC 8259). It doesn't support JSON5 features like comments, trailing commas, or unquoted keys. Use a dedicated JSON5 parser for those formats.
Can I validate JSON structure without formatting? ▼
Yes! Paste your JSON and if there are syntax errors, you'll see error messages. If it's valid, you can choose to format it or leave it as-is.