1. Paste your JSON into the input editor.
2. Auto-validate checks syntax in real-time (or click Validate manually).
3. Format to beautify with proper indentation (2 or 4 spaces).
4. Minify to compress JSON into a single line for production.
5. Sort Keys alphabetically for consistent diffs and version control.
6. Tree View to explore nested objects and arrays visually.

Why use a JSON formatter?

• Catch errors fast: See exactly which line has syntax problems with red indicators and detailed error messages.
• Better readability: Properly indented JSON is easier to understand and debug.
• Save time: No need to manually count brackets or hunt for missing commas.
• Professional workflow: Side-by-side input/output layout like VS Code.
• Learn JSON: Error hints explain common mistakes (trailing commas, unquoted keys, single quotes).

Key features

Real-time validation

• Auto-validate mode checks syntax as you type
• Line-by-line error highlighting with red dots in the gutter
• Hover tooltips show error details when you mouse over problem lines
• Error panel lists all issues with clickable line numbers

Multiple views

• Formatted view: Beautifully indented JSON with syntax highlighting
• Tree view: Collapsible nodes showing object/array structure with item counts
• Line numbers: Synced gutters for easy navigation

Formatting options

• Indent size: Choose 1, 2, or 4 spaces
• Minify: Remove all whitespace for compact output
• Sort keys: Alphabetize object properties recursively
• Swap: Instantly switch input and output

Developer-friendly

• VS Code color scheme: Familiar syntax highlighting for light and dark themes
• Keyboard-friendly: All controls accessible via buttons
• Stats display: See byte count and line count
• Copy/download: Get formatted JSON ready for your code

Common JSON errors explained

The validator catches and explains these mistakes:

• Trailing commas: ["item1", "item2",] — JSON doesn't allow commas after the last element
• Single quotes: {'key': 'value'} — JSON requires double quotes only
• Unquoted keys: {key: "value"} — All keys must be in double quotes
• Comments: // comment or /* comment */ — JSON doesn't support comments
• Duplicate keys: Same property name twice in an object
• Invalid root: JSON must start with { or [, not a primitive value

Use cases

API development: Validate and format API responses before writing tests or documentation.

Configuration files: Clean up config JSON for better readability and version control.

Data analysis: Explore complex nested structures without writing code.

Learning: Understand JSON syntax by seeing exactly what's wrong and why.

Code reviews: Format JSON consistently across your team for easier diffs.

Debugging: Quickly spot syntax errors in large JSON files.

Best practices

• Use consistent indentation (2 or 4 spaces) across your project
• Sort keys before committing to git for cleaner diffs
• Minify JSON for production APIs to reduce bandwidth
• Validate before deploying to catch syntax errors early
• Remove comments if you're using JSON5 or JSONC in development

Privacy & security

All processing happens locally in your browser. Your JSON data never leaves your device — no server uploads, no logging, no tracking. Safe for sensitive data, API keys, and confidential configurations.

Final thoughts

Clean, valid JSON is essential for modern development. With JSON Formatter & Validator, you get a professional editor experience right in your browser — no extensions, no downloads, just paste and format. Whether you're debugging an API, cleaning config files, or learning JSON syntax, this tool makes the job faster and easier.