JSON Formatter Online Free

The fastest online JSON formatter — paste any JSON and instantly format JSON online with syntax highlighting, tree view and pretty print. Also validates, minifies and converts JSON. Our client-side JSON formatter runs entirely in your browser. No uploads, no account, 100% private.
JSON Beautifier · JSON Validator · JSON Pretty Print · Tree View · Free

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Input JSON
Formatted Output

How It Works

1. Paste JSON

Paste any raw, minified or malformed JSON into the left panel.

2. Format

Click Format & Beautify to pretty print with syntax highlighting.

3. Explore

Switch to Tree View to navigate nested objects and arrays interactively.

4. Copy or Download

Copy the formatted JSON to clipboard or download it as a .json file.

What Is an Online JSON Formatter?

A JSON formatter online takes raw, minified or unstructured JSON text and re-formats it with consistent indentation, line breaks and spacing — making nested objects and arrays visually clear and easy to navigate. This process is also called JSON beautification or JSON pretty printing.

Our free online JSON formatter and validator does more than just format — it also validates your JSON for syntax errors, minifies it for production use, and provides an interactive JSON tree view for navigating deeply nested data structures. All processing runs locally in your browser, making it a true client-side JSON formatter no upload tool — your data never leaves your device.

Key Features

JSON FormatterPretty print with 2-space, 4-space or tab indentation
JSON ValidatorReal-time syntax error detection with error messages
JSON Tree ViewNavigate nested objects and arrays interactively
JSON MinifierRemove all whitespace for production-ready output
Syntax HighlightingKeys, strings, numbers, booleans and null highlighted
100% Client-SideYour JSON never leaves your browser

How to Format and Validate JSON Online

Using this JSON beautifier and validator is straightforward. Here's a guide to each feature:

Format JSON with Indentation and Syntax Highlighting

Paste your JSON into the left panel and click Format & Beautify. The output appears with colour-coded syntax highlighting — purple for keys, blue for strings, dark blue for numbers, bold for booleans. Choose between 2 spaces, 4 spaces or tab indentation using the buttons above the editor.

// Input — minified JSON: {"name":"Alice","scores":[95,87,92],"active":true} // Output — formatted with 2-space indent: { "name": "Alice", "scores": [ 95, 87, 92 ], "active": true }

JSON Tree View

After formatting, click the Tree View tab in the output panel to switch to an interactive collapsible tree. Click the ▶ arrows to expand or collapse any object or array. The tree view shows the count of items in each node, making it easy to navigate large or deeply nested JSON structures — exactly like beautify JSON with tree view.

Validate JSON

Click Validate to check whether your JSON follows the correct syntax. The status bar shows a green dot for valid JSON and a red dot with the error message for invalid JSON. Common errors include missing commas, trailing commas after the last item, unquoted keys, single quotes instead of double quotes, and mismatched brackets.

Minify JSON

Click Minify to strip all whitespace from your JSON, producing the most compact representation possible. The status bar shows how many characters were removed. Minified JSON is ideal for API responses and production builds where bandwidth and file size matter.

Who Uses a JSON Formatter?

This JSON formatter for developers is used across many fields and workflows:

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Frequently Asked Questions

A JSON formatter takes raw or minified JSON text and re-formats it with proper indentation, line breaks and spacing — making nested objects and arrays visually structured and easy to read. This is also called JSON beautification or JSON pretty print. The formatter also validates the JSON and reports syntax errors with helpful messages.
Paste your JSON into the left panel and click Format & Beautify. The formatted JSON appears in the output panel with syntax highlighting. Choose your indentation preference (2 spaces, 4 spaces or tab) using the buttons above. All formatting happens in your browser — no upload required.
JSON pretty print is the process of formatting JSON with consistent indentation and line breaks so nested structures are visually clear. For example, {"a":1,"b":[2,3]} becomes a multi-line formatted document with each key on its own line, indented according to its nesting level. This tool supports 2-space, 4-space and tab indentation.
After formatting your JSON, click the Tree View tab in the output panel. The JSON is rendered as an interactive collapsible tree — click the ▶ arrow on any object or array to expand or collapse it. Each node shows the number of keys or items it contains. This makes it easy to navigate large or deeply nested JSON without scrolling through raw text.
Yes. This is a client-side JSON formatter no upload — all formatting, validation, minification and tree rendering happens locally in your browser using JavaScript. Your JSON data is never sent to any server, stored anywhere, or shared with any third party. It works offline once the page is loaded.
Format re-arranges valid JSON with indentation and line breaks for readability. Validate checks whether the JSON follows correct syntax rules — proper bracket pairing, quoted keys, valid value types (string, number, boolean, null, array, object), no trailing commas. Clicking Format & Beautify does both simultaneously — it validates first and formats only if the JSON is valid.