JSON Formatter Validator Tool - Online JSON Beautifier Minifier and Tree Viewer

First Published:
Last Updated:

Free online JSON formatter, validator, beautifier, minifier, and tree viewer. All processing is performed entirely in your browser - your JSON data never leaves your device.

⚠️ IMPORTANT DISCLAIMER:

  • This tool is provided "AS IS" without any warranties of any kind.
  • The author accepts no responsibility for data loss or any issues arising from use of this tool.
  • Do not paste sensitive or confidential data without understanding that all processing is local.
  • Always keep backups of your original data.
  • By using this tool, you accept full responsibility for any outcomes.

This tool uses client-side JavaScript for all processing. No data is transmitted to servers, no files are uploaded online, all processing happens locally in your browser. Once loaded, this tool continues to work even without an internet connection. For more details, please refer to our Web Tools Disclaimer.

📁 Drop a JSON file here, or click to select a file (max 5MB) 

    

    
  


  

    
  


  









Features:


    
  
  • ✨ Format / Beautify: Pretty-print JSON with configurable indentation (2 spaces, 4 spaces, or tabs)
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  • 🗜️ Minify / Compress: Remove all whitespace to produce compact JSON output
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  • ✅ Validate: Check JSON syntax with detailed error location (line and column number)
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  • 🌳 Tree View: Interactive collapsible tree visualization of JSON structure
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  • 📁 File Support: Drag and drop or select JSON files up to 5MB
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  • 📊 Statistics: View JSON size, type, key count, and nesting depth
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  • 📋 Easy Copy: One-click copy of formatted or minified output
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  • 📱 Mobile Friendly: Responsive design works on all devices
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  • 🔒 Privacy First: All processing happens locally in your browser - no data sent to servers
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  • ⌨️ Keyboard Shortcut: Ctrl+Enter (Cmd+Enter) to format instantly
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Common Use Cases:


    
  
  • API Development: Format and validate JSON responses from REST APIs
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  • Configuration Files: Validate JSON config files before deployment
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  • Data Analysis: Explore complex JSON structures with the tree viewer
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  • Debugging: Find syntax errors in JSON payloads with precise error location
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  • Data Transfer: Minify JSON to reduce payload size for network transmission
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References: 

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Written by Hidekazu Konishi