JSON Formatter
Free online JSON formatter. Validate, beautify, minify JSON instantly. No signup required.
📋 What is JSON Formatter?
JSON (JavaScript Object Notation) is the most widely used lightweight format for data exchange. JSON Formatter prettifies compressed JSON with indentation and line breaks for readability, or minifies it by removing unnecessary whitespace. It is an essential tool for API response analysis, config file editing, database record inspection, and debugging throughout development workflows.
🔧 Key Features
Format (Prettify)
Indent compressed JSON with 2/4 spaces or tabs for readability
Minify
Remove whitespace and line breaks to minimize file size
Validation
Detect JSON syntax errors with specific location and cause hints
Real-time Conversion
Auto-format as you type (300ms debounce)
💡 JSON Syntax Rules
- Keys must be wrapped in double quotes (single quotes not allowed)
- String values use double quotes; numbers/booleans/null do not
- Trailing commas after the last item are not allowed
- Comments are not supported (JSON5, JSONC do support them)
Frequently Asked Questions
What is the difference between JSON and JavaScript objects?▼
JSON is a data exchange format requiring double-quoted keys and does not support functions, undefined, or comments. JavaScript objects are more flexible but must follow JSON rules when serializing.
What is the standard indentation size?▼
There is no official standard. 2 spaces is most common, 4 spaces is also popular. Follow your project coding conventions.
How can I add comments to JSON?▼
Standard JSON does not support comments. For config files, use JSONC (JSON with Comments) or JSON5 format, or use workarounds like a "_comment" key.
What is JSON Formatter?
Format and beautify JSON with proper indentation and syntax highlighting. Validates JSON structure and shows clear error messages. Supports minification for compact output.