JSON Formatter

Pretty-print, validate, and minify JSON. Sort keys, adjust indentation, and see compression stats. Free, instant, 100% private.

About JSON Formatter

Format and beautify JSON data with adjustable indentation, key sorting, and minification. Validate syntax with detailed error messages showing line and column numbers. All processing happens in your browser — no data is ever uploaded.

Smart Formatting

Auto-indent JSON with adjustable spacing (2, 4, or tab). Makes nested data readable instantly, perfect for debugging API responses.

Key Sorting

Sort object keys alphabetically for consistent, organized output. Great for configuration files and comparing JSON structures.

Real-time Validation

Detects syntax errors with exact line and column numbers. Fix malformed JSON quickly without guesswork.

100% Private

All processing in your browser. No uploads, no servers. Your sensitive API responses, configs, and data never leave your device.

📋 Common Use Cases

Debugging API Responses

Paste raw API response JSON to pretty-print and inspect nested structures when troubleshooting endpoint output.

Preparing Configuration Files

Format minified JSON configs from package.json or docker-compose files into human-readable layouts for editing.

Validating JSON Before Deployment

Run a syntax check on JSON files before pushing to production to catch trailing commas, missing brackets, or invalid types.

Compressing JSON for Storage

Minify bulky JSON payloads to reduce file size when storing logs or transferring data over bandwidth-constrained connections.

🪜 How to Use This Tool

  1. Paste or type your JSON
    Copy any JSON string and paste it into the input area — the tool accepts raw text from any source.
  2. Choose a mode
    Select Format for pretty-printing, Validate to check syntax only, or Minify to compress the output.
  3. Review errors if any
    Invalid JSON highlights the exact line and character where the parser found a problem, with a plain-English hint.
  4. Copy the result
    Use the copy button to grab formatted, validated, or minified output and paste it wherever you need.

📚 Related Guides

Frequently Asked Questions

Are these dev tools free?▼
Yes. All dev tools are completely free. No signup, no account.
Is my data sent to a server?▼
No. Base64 encoding, URL encoding, JWT decoding, hash generation, and regex testing all happen in your browser. Your tokens and secrets stay on your device.
Can I decode JWTs safely?▼
Yes. JWT decoding happens entirely in your browser. The token never leaves your device. Only the header and payload are decoded — signatures are not verified server-side.