JSON Formatter & Validator

Format, validate, beautify, and minify JSON instantly. Paste or upload your JSON and view it as a collapsible tree. 100% free, no registration, fully browser-based.

Waiting for input...
Drop JSON files here or click Upload

Privacy First

All formatting and validation happen locally in your browser. No data is uploaded or stored.

Accurate Validation

Instant JSON validation with precise error index mapped to line and column for quick fixes.

Collapsible Viewer

Switch to Tree view to explore nested JSON with collapsible nodes using a clean, readable layout.

How to Format JSON

1

Paste or Upload

Paste JSON into the editor or upload a .json/.txt file. Drag & drop is supported.

2

Choose Options

Set indentation size, enable key sorting, and toggle live validation as needed.

3

Format & View

Click Format or Minify, then copy or download the result. Explore structure in Tree view.

What is JSON Formatter & Validator?

JSON Formatter & Validator is a free online tool to beautify, validate, and minify JavaScript Object Notation (JSON). It helps developers and users quickly inspect and correct JSON by providing pretty printing, error locations, key sorting, and a collapsible tree viewer.

Instant
Validation
Tree
Viewer
100%
Browser-Based

Key Features

Feature Our Tool Traditional Tools
Validation βœ… Error index βœ… line & column ❌ Vague error messages
Beautify/Minify βœ… Indent: 2/4/Tabs ❌ Fixed formatting only
Key Sorting βœ… Recursive sort ❌ Limited or absent
Viewer βœ… Collapsible tree ❌ Flat output
Privacy βœ… 100% Browser-Based ❌ Server Upload Required

Common Use Cases

Use Case Benefits Notes
πŸ”Œ API Debugging
Inspect API responses
Pretty print & validate Find malformed JSON quickly
βš™οΈ Config Files
Edit app settings
Beautify & sort keys Improves readability
πŸ§ͺ Test Data
Craft fixtures
Minify for storage Consistent formatting
πŸ“ Documentation
Example payloads
Clean, readable JSON Copy & download easily

Security and Privacy

Your privacy is our priority. All processing occurs locally in your browser using JavaScript. No JSON is uploaded, stored, or transmitted.

Troubleshooting

Unexpected token error

Check for trailing commas, unquoted keys, or single quotes. The error index maps to the exact line and column.

Large files

For very large JSON, prefer Tree view and disable live validation to improve responsiveness.

Encoding issues

Ensure input is UTF-8. Convert other encodings to UTF-8 before formatting.

Alternative Tools

You might also consider:

CSV to JSON

Convert tabular data to JSON

JSON to CSV

Transform JSON objects to rows

Text Formatter

Clean and structure plain text

Relevant Tools

Quickly jump to related developer and data tools to continue your workflow without leaving the site.

Usage Rules & Requirements

πŸ“ Input Requirements

  • Supported input: JSON strings or files (.json/.txt)
  • Maximum recommended size: ~10MB
  • Valid UTF-8 encoding
  • Standard JSON syntax only

🌐 Browser Compatibility

  • Modern browsers with JavaScript enabled
  • Chrome, Firefox, Edge, Safari, Opera
  • Minimum 512MB RAM recommended
  • Best viewed on desktop for large JSON

πŸ”’ Privacy & Security

  • All processing happens locally
  • No uploads or external APIs
  • No data stored or transmitted
  • 100% browser-based formatting

⚑ Performance Guidelines

  • Disable live validation for very large files
  • Use Tree view to navigate nested data
  • Minify to reduce file size
  • Sorting keys may increase processing time

Important: This tool is provided as-is for personal and commercial use. While we strive for accuracy, please verify formatted data before use in production environments.