JSON Formatter & Validator

JSON Formatter & Validator

Paste your JSON below. Use the toolbar to format, minify, sort keys, or repair. The output panel shows syntax-highlighted code, an interactive tree view, and detailed stats.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight, human-readable data interchange format. It represents data as key-value pairs (objects) and ordered lists (arrays), using only six data types: strings, numbers, booleans (true/false), null, objects ({}), and arrays ([]). JSON is the dominant format for REST APIs, configuration files, and data storage across virtually all programming languages and platforms.

How to Use the JSON Formatter

1. Paste your JSON into the input area above.
2. Click Format & Validate — or enable Live mode to auto-format as you type.
3. If the JSON is valid, the output shows syntax-highlighted formatted code, an interactive tree view, and detailed stats.
4. If the JSON is invalid, a red error banner shows the exact error message and location to help you fix it. Try Repair for common fixes.
5. Use Minify to compress JSON by removing all whitespace for use in APIs or storage.
6. Use Sort Keys to alphabetically sort all object keys at every level.
7. Switch to Tree View to explore nested JSON interactively — click arrows to expand or collapse nodes.

Key Features

• Syntax highlighting: Keys, strings, numbers, booleans, and null values each have distinct colors.
• Validation with error location: Shows the exact error message and line/column hint from JSON.parse().
• Interactive tree view: Collapsible nodes for exploring deeply nested JSON structures.
• Format / Minify / Sort Keys / Repair: Four one-click transformation actions.
• Configurable indent: Choose 2 spaces, 4 spaces, or tab indentation.
• Stats panel: Total keys, values, nesting depth, arrays, objects, strings, numbers, booleans, nulls, and size.
• Live mode: Real-time formatting as you type.
• Copy formatted, copy minified, download .json.
• 100% browser-based: No data is sent to any server.

Common JSON Errors

• Trailing commas: {"a":1,} — JSON does not allow trailing commas after the last item.
• Single quotes: {'key':'value'} — JSON requires double quotes for both keys and string values.
• Unquoted keys: {key:"value"} — All object keys must be quoted strings.
• Comments: JSON does not support // or /* */ comments.
• Undefined / functions: JSON supports only strings, numbers, booleans, null, objects, and arrays — not undefined, functions, or dates.
• Mismatched brackets: Every { must have a matching } and every [ a matching ].