JSON Editor

Getting Started

Follow these simple steps to format, validate, and edit JSON data online:

• Step 1: Switch to the Utility tab at the top of the page.
• Step 2: Paste or type your JSON data into the Raw JSON panel on the left.
• Step 3: Click the right arrow between the panels to sync the raw JSON into the interactive Tree View.
• Step 4: Edit values, keys, or structure in either panel. Use the left arrow to sync tree edits back to raw JSON.

Formatting & Minifying JSON

Use the toolbar buttons above the Raw JSON panel to transform your JSON:

• Format (Pretty Print) — Reformats your JSON with 2-space indentation, making it easy to read and debug. Perfect for beautifying minified API responses or compact JSON files.
• Minify — Compresses your JSON into a single line with no whitespace. Useful for reducing file size before sending JSON over a network or storing in a database.

Example: Sample JSON

Try pasting this sample JSON to explore the editor features:

• {
  "name": "Online Text Tools",
  "version": "1.0",
  "features": ["format", "validate", "edit", "minify"],
  "settings": {
    "theme": "dark",
    "autoSync": true,
    "maxDepth": 10
  }
}

After pasting, click the sync arrow to see it rendered as an interactive tree. Try clicking a value to edit it, or double-clicking a key to rename it.

JSON Validation

Validation happens automatically as you type in the Raw JSON panel. The editor provides instant feedback:

• Valid JSON — The tree view updates to show the parsed structure. No error messages are displayed.
• Invalid JSON — An inline error appears at the exact line where the syntax problem is, with a description of what went wrong (e.g., missing comma, unexpected token, unterminated string).

Common JSON syntax errors include missing commas between properties, trailing commas after the last property, unquoted keys, and single quotes instead of double quotes.

Tree View Editing

The interactive tree view lets you edit JSON visually without writing raw text:

• Edit Values — Single-click any value to edit it inline. Press Enter or click away to save.
• Rename Keys — Double-click any key name to rename it.
• Duplicate Nodes — Hover over a node and click the duplicate button to create a copy.
• Remove Nodes — Hover over a node and click the remove button to delete it.
• Navigate with Tab — Use the Tab key to move between editable fields.
• Expand / Collapse — Click the arrow next to any object or array to expand or collapse its children. Use "Expand All" and "Collapse All" buttons to control all nodes at once.

Syncing Between Panels

The Raw JSON and Tree View panels are linked through the sync gutter in the center:

• Right arrow — Parses the raw JSON and renders it in the tree view. Use this after pasting or editing raw JSON.
• Left arrow — Serializes the tree back to formatted raw JSON. Use this after making edits in the tree view.

Syncing is manual so you can make multiple edits before committing changes to the other panel.

Search

Both panels include a search field to help you find keys, values, or text within your JSON:

• Raw JSON Search — Highlights matching text in the raw editor. Use it to find specific strings, numbers, or patterns.
• Tree View Search — Filters and highlights matching nodes in the tree. Matching keys and values are visually emphasized.

File Operations

Use the toolbar buttons to manage your JSON files:

• Load — Upload a .json file from your device directly into the editor.
• Copy — Copy the raw JSON to your clipboard with a single click.
• Download — Save the current JSON as a .json file to your device.
• Clear — Reset the editor and start fresh.

Example: Format JSON (Pretty Print)

Paste a minified JSON string and click Format to see it transformed into readable, indented output:

Input (minified):

• {"users":[{"id":1,"name":"Alice","role":"admin"},{"id":2,"name":"Bob","role":"editor"}],"total":2}

Output (formatted with 2-space indentation):

• {
  "users": [
    {
      "id": 1,
      "name": "Alice",
      "role": "admin"
    },
    {
      "id": 2,
      "name": "Bob",
      "role": "editor"
    }
  ],
  "total": 2
}

The formatted output uses 2-space indentation with each key-value pair on its own line. Array items and nested objects are indented to show the hierarchy clearly.

Example: Minify JSON

Click Minify to compress formatted JSON into a single compact line:

Input (formatted, 15 lines):

• {
  "name": "Alice",
  "age": 30,
  "active": true
}

Output (minified, 1 line):

• {"name":"Alice","age":30,"active":true}

Minification removes all unnecessary whitespace — spaces after colons, spaces after commas, newlines, and indentation — while preserving the data exactly. This is useful for reducing JSON payload size before sending it over a network or storing it in a database field.

Example: Tree View Editing Walkthrough

Here is a step-by-step walkthrough of editing JSON in the tree view:

• Step 1: Paste {"product": "Laptop", "price": 999, "inStock": true} into the Raw JSON panel.
• Step 2: Click the right arrow in the sync gutter to load the tree view. You will see three nodes: "product", "price", and "inStock".
• Step 3: Single-click the value 999 next to "price". The value becomes editable. Type 1099 and press Enter.
• Step 4: Double-click the key "product". It becomes editable. Rename it to "productName" and press Enter.
• Step 5: Hover over the "inStock" node. Click the duplicate button that appears. A copy named "inStock_copy" is created.
• Step 6: Hover over the duplicated "inStock_copy" node. Click the remove button to delete it.
• Step 7: Click the left arrow in the sync gutter to sync your edits back to the Raw JSON panel. The raw text now shows {"productName": "Laptop", "price": 1099, "inStock": true}.

The tree view automatically detects value types — strings remain strings, numbers remain numbers, and booleans remain booleans. If you edit a numeric value like 999 and type "nine hundred", it will be stored as a string because of the quotes.

Keyboard Shortcuts

The JSON editor supports keyboard navigation for efficient editing:

Raw JSON Editor:

• Tab — Inserts 2 spaces at the cursor position (instead of moving focus). This makes it easy to indent JSON manually.

Tree View Navigation:

• Arrow Down / Arrow Up — Move focus to the next or previous visible node in the tree. Collapsed children are automatically skipped.
• Arrow Right — Expand the currently focused node (if it is an object or array).
• Arrow Left — Collapse the currently focused node.
• Enter — Start editing the value of the currently focused node.
• Delete — Remove the currently focused node from its parent.

Inline Editing (when editing a key or value):

• Enter — Commit the edit and stop editing.
• Escape — Cancel the edit and revert to the previous value.
• Tab — Commit the current edit and move to the next editable field.
• Shift + Tab — Commit the current edit and move to the previous editable field.

Syntax Highlighting

The raw JSON editor includes real-time syntax highlighting to make your JSON easier to read. Different elements are color-coded:

• Keys — Displayed in blue, making them easy to distinguish from values.
• Strings — Displayed in green, including the surrounding double quotes.
• Numbers — Displayed in blue to stand out from string values.
• Booleans (true/false) — Displayed in orange for quick identification.
• null — Displayed in gray to indicate empty or missing values.
• Brackets, colons, commas — Displayed in the default text color for structural clarity.

The syntax highlighting updates in real time as you type, and the highlight overlay scrolls in sync with the text area so colors always align with the corresponding text.

Line Numbers

The raw JSON editor displays line numbers along the left edge for easy reference. Line numbers update automatically as you type and scroll in sync with the text area. When a validation error occurs, the inline error message references the specific line number where the problem was found, so you can jump directly to the issue.

Auto-Collapse for Large JSON

When you first sync JSON to the tree view, nodes deeper than 2 levels are automatically collapsed to keep the tree manageable. For example, in a JSON structure like {"a": {"b": {"c": {"d": "deep value"}}}}, the nodes "a" and "b" will be expanded, but "c" and deeper will be collapsed. You can expand them manually by clicking the arrow or pressing the Right Arrow key.

After the first render, the tree preserves your expand/collapse choices across re-renders, so your view stays stable as you make edits.

Use Cases for JSON Editing

Our free JSON editor online is useful for developers, testers, and anyone working with JSON data:

• API Development — Format and inspect API request and response payloads to debug integration issues.
• Configuration Files — Edit package.json, tsconfig.json, or other config files with a visual tree for easier navigation.
• Data Transformation — Quickly modify JSON data structures, rename keys, or remove unnecessary fields.
• Learning JSON — Students can use the tree view to understand JSON structure visually — objects, arrays, nested properties, and data types.
• Data Validation — Paste JSON from any source to instantly check if it is valid and identify syntax errors.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. Originally derived from JavaScript, JSON is now language-independent and supported by virtually every modern programming language including Python, Java, C#, Go, Ruby, and PHP.

JSON is built on two universal data structures:

• Objects — An unordered collection of key-value pairs, written as {"key": "value"}. Keys must be strings enclosed in double quotes. Values can be strings, numbers, booleans, null, arrays, or nested objects.
• Arrays — An ordered list of values, written as ["apple", "banana", "cherry"]. Array elements can be any valid JSON data type, including mixed types and nested structures.

JSON has become the standard data format for web APIs, configuration files, and data storage. It replaced XML in many applications because of its simpler syntax, smaller file size, and native compatibility with JavaScript. Today, most REST APIs return JSON by default, and popular tools like package.json (Node.js), tsconfig.json (TypeScript), and settings.json (VS Code) all use JSON for configuration.

JSON Data Types

JSON supports six data types. Understanding these types is essential for writing valid JSON:

• String — Text enclosed in double quotes: "hello world". Supports escape sequences like \n (newline), \t (tab), \" (escaped quote), and \\ (backslash).
• Number — Integer or floating-point: 42, 3.14, -7, 1.5e10. No leading zeros, no hex, no NaN or Infinity.
• Boolean — Either true or false (lowercase only, no quotes).
• Null — Represents an empty or unknown value: null (lowercase, no quotes).
• Object — A collection of key-value pairs: {"name": "Alice", "age": 30}.
• Array — An ordered list of values: [1, 2, 3] or ["red", "green", "blue"].

Common JSON Errors and How to Fix Them

Even experienced developers encounter JSON syntax errors. Here are the most common mistakes and how to fix them using our JSON validator online:

• Trailing comma — JSON does not allow a comma after the last item in an object or array. {"a": 1, "b": 2,} is invalid. Remove the trailing comma to fix it.
• Single quotes instead of double quotes — JSON requires double quotes for all strings and keys. {'name': 'Alice'} is invalid. Use {"name": "Alice"} instead.
• Unquoted keys — All keys must be quoted strings. {name: "Alice"} is invalid. Use {"name": "Alice"}.
• Missing commas — Each key-value pair or array element must be separated by a comma. {"a": 1 "b": 2} is invalid. Add a comma: {"a": 1, "b": 2}.
• Comments — JSON does not support comments. {"a": 1 // this is a comment} is invalid. Remove all comments before parsing. If you need comments, consider using JSONC or JSON5 formats.
• Undefined or NaN values — undefined, NaN, and Infinity are not valid JSON values. Use null for missing values and regular numbers for numeric values.
• Unescaped special characters — Backslashes, newlines, and tabs inside strings must be escaped: \\, \n, \t. A literal newline inside a string will cause a parse error.

Paste your JSON into our editor to instantly see the exact line and description of any syntax error.

JSON vs XML — When to Use Each

JSON and XML are both popular data interchange formats, but they serve different needs:

• Syntax — JSON uses a compact key-value syntax that is typically 30-50% smaller than equivalent XML. XML uses verbose opening and closing tags for every element.
• Readability — JSON is generally easier to read for simple data structures. XML can be more readable for document-like content with mixed text and markup.
• Data types — JSON natively supports strings, numbers, booleans, null, objects, and arrays. XML treats everything as text and relies on schemas for type information.
• Attributes — XML supports attributes on elements (e.g., <book id="1">). JSON has no concept of attributes — everything is a key-value pair.
• Comments — XML supports comments (<!-- comment -->). Standard JSON does not allow comments.
• Use JSON when — Building REST APIs, web applications, mobile apps, configuration files (package.json, tsconfig.json), or any modern data exchange.
• Use XML when — Working with SOAP web services, document formats (XHTML, SVG, RSS), enterprise systems, or when you need schema validation (XSD) and transformation (XSLT).

JSON Best Practices

Follow these best practices to write clean, maintainable JSON:

• Use consistent naming conventions — Choose camelCase (firstName) or snake_case (first_name) and use it consistently throughout your JSON. Most JavaScript APIs use camelCase, while Python APIs often use snake_case.
• Keep nesting shallow — Deeply nested JSON (5+ levels) is hard to read and maintain. Flatten your data structure where possible.
• Use meaningful key names — Prefer descriptive keys like "emailAddress" over abbreviated ones like "ea". This makes your JSON self-documenting.
• Validate before sending — Always validate JSON before sending it to an API or saving it to a file. Use our JSON validator to catch syntax errors early.
• Minify for production — Use pretty-printed JSON during development for readability, and minified JSON in production to reduce bandwidth and improve performance.
• Use null for missing values — Use null to represent missing or unknown values rather than empty strings or omitting the key entirely. This makes the schema predictable.

Privacy

Your JSON data is processed entirely in your browser using JavaScript. Nothing is ever sent to any server — your data stays on your device, always. There is no tracking, no account required, and no data collection of any kind. Learn more in our Privacy Policy.

Frequently Asked Questions

How do I format JSON online for free?

Paste your JSON into the Raw JSON panel and click the Format button. The JSON will be pretty-printed with 2-space indentation. The tree view updates automatically to show the structured data.

How do I validate JSON online?

Paste or type JSON in the editor — validation happens automatically as you type. Valid JSON shows a green status. Invalid JSON shows an inline error at the exact line with a description of the syntax problem.

Can I edit JSON in the tree view?

Yes. Single-click any value to edit it inline. Double-click a key to rename it. You can also duplicate or remove any node using the action buttons that appear on hover. Use Tab to move between fields.

Does this JSON editor work with large files?

Yes. The editor uses adaptive debouncing and efficient rendering. Nodes deeper than 2 levels are auto-collapsed on first load to keep the tree manageable. You can expand them on demand.

Is my JSON data safe in this online editor?

Your JSON never leaves your device. All parsing, formatting, validation, and editing happens locally in your browser — no data is sent to any server. Learn more in our Privacy Policy.

Can I minify JSON online?

Yes. Click the Minify button to compress your JSON into a single line with no whitespace. This is useful for reducing file size before sending JSON over a network.