JSON Editor Online

Edit, format, validate, and transform JSON with dual-pane editor interface

About JSON Editor Online

Overview

JSON Editor Online is a powerful dual-pane JSON editor that allows you to view, edit, format, validate, and transform JSON data in real-time. With side-by-side editors, you can easily compare, modify, and transform JSON while maintaining your workflow. All changes are automatically saved to your browser for convenience.

Features

  • Dual Monaco editor interface with syntax highlighting
  • Real-time JSON validation with error messages
  • Beautify and format JSON with proper indentation
  • Minify JSON to reduce file size
  • Sort object keys alphabetically
  • Repair common JSON syntax errors
  • Auto-save to localStorage for data persistence
  • File upload and download support
  • Drag-and-drop file handling
  • Copy to clipboard functionality
  • Dark mode support
  • Line numbers and minimap for navigation
  • Completely browser-based - no server uploads

How to Use

  1. Paste or type your JSON in the left editor
  2. Use transform buttons to beautify, minify, sort keys, or validate your JSON
  3. View the transformed result in the right editor
  4. Upload JSON files via drag-and-drop or file picker
  5. Download your edited JSON with one click
  6. Copy JSON to clipboard or swap between editors

FAQ

What is the difference between beautify and minify?

Beautify formats JSON with proper indentation and line breaks, making it human-readable. Minify removes all unnecessary whitespace and line breaks, creating the smallest possible JSON string. Use beautify for reading and editing, minify for production or transmission to reduce file size.

How does the repair feature work?

The repair feature attempts to fix common JSON errors like missing quotes, trailing commas, and single quotes instead of double quotes. It uses heuristics to identify and correct common syntax mistakes. However, it may not fix all errors, especially complex structural issues.

Is my JSON data saved permanently?

Your JSON is saved to your browser's localStorage, which persists until you clear your browser data or use the "Clear" button. The data never leaves your device and is not uploaded to any server. For permanent storage, download your JSON file.

Can I edit both sides simultaneously?

Yes, both editors are fully editable. You can work on different JSON structures in each editor and use transform buttons to copy or compare between them. This is useful when working with before/after states or comparing different JSON structures.

What happens if I paste invalid JSON?

The editor will show error messages indicating where the JSON syntax is incorrect. You can use the repair feature to attempt automatic fixes, or manually correct the errors using the error messages as guidance. The validation runs in real-time as you type.