JSON Formatter & Validator

Format, validate, and minify JSON entirely in your browser. Your data never leaves your device.

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Formatted JSON will appear here...

All Tools

Privacy-first developer utilities that run entirely in your browser

Diff Checker

Compare text and code differences side-by-side with syntax highlighting. Perfect for code reviews and file comparisons.

JSON Formatter

Format, validate, and beautify JSON data instantly. Minify or prettify with proper indentation.

Base64 Encoder

Encode and decode Base64 strings securely in your browser. No server uploads required.

UUID Generator

Generate UUID v4 identifiers instantly. Bulk generation supported for database seeding and testing.

Code Screenshot

Create beautiful code screenshots with syntax highlighting and customizable themes for documentation.

Package Size

Check npm package bundle sizes and analyze dependencies before adding them to your project.

Why Use a Client-Side JSON Formatter?

Most online JSON formatters upload your data to their servers, exposing sensitive API responses, configuration files, and proprietary data. Our JSON formatter processes everything locally in your browser using JavaScript - nothing is ever transmitted over the network.

  • 100% Private: Your JSON never leaves your device
  • Instant Results: No server round-trips, just pure client-side processing
  • Works Offline: Format JSON even without an internet connection
  • Free Forever: No accounts, no limits, no tracking

Features

Format & Prettify

Transform minified JSON into human-readable format with customizable indentation (2, 4, or 8 spaces).

Minify & Compress

Remove all whitespace to create the smallest possible JSON for production deployments.

Validate JSON

Quickly check if your JSON is valid and get precise error messages pointing to syntax issues.

Sort Keys

Alphabetically sort object keys for easier comparison and consistent formatting.

Common Use Cases

  • Format API responses from curl or Postman
  • Validate JSON configuration files (package.json, tsconfig.json, etc.)
  • Minify JSON before deploying to production
  • Debug malformed JSON from external APIs
  • Compare JSON structures by sorting keys consistently

How It Works

  1. Paste your JSON into the input area
  2. Click Format, Minify, or Validate
  3. The JSON is processed entirely in your browser using JavaScript's native JSON.parse() and JSON.stringify()
  4. Results appear instantly in the output area
  5. Copy the formatted result or clear to start over

Privacy Note: Open your browser's Network tab (F12) and you'll see zero network requests. Your data stays on your device.