JSON Formatter

Format, validate, and beautify JSON instantly. All processing happens in your browser.

Shortcut: Cmd + Enter

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Input

Output

Tips

Paste JSON from API responses, config files, or package.json to format instantly.
Use Tree View to drill into deeply nested objects without losing context.
Minify before sending over the network to reduce payload size by 30-60%.
Validation errors show exact line and column numbers to help you find issues quickly.
Press Cmd+Enter to re-format the current input.

Why format your JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format that has become the standard for data communication on the web. Originally derived from JavaScript, JSON is now language-independent and supported by virtually every modern programming language. Its simplicity and readability make it the preferred format for REST APIs, configuration files, and data storage.

A valid JSON document must follow strict syntax rules. Data is organized into key-value pairs within objects (denoted by curly braces) or ordered lists of values within arrays (denoted by square brackets). Keys must always be strings wrapped in double quotes. Values can be strings, numbers, booleans (true or false), null, objects, or arrays. Unlike JavaScript, JSON does not support comments, trailing commas, or single-quoted strings.

Formatting (or "beautifying") JSON adds consistent indentation and line breaks, making complex nested structures much easier to read and debug. Minifying JSON removes all unnecessary whitespace, reducing file size for network transmission. Both operations are lossless, meaning the underlying data remains identical.

The tree view representation breaks JSON into a hierarchical, expandable structure. This is especially useful when inspecting deeply nested data, as you can collapse sections you do not need and focus on specific branches. The tree view also shows the type of each value at a glance.

Common JSON errors include missing commas between key-value pairs, unescaped special characters inside strings, trailing commas after the last element, and mismatched braces or brackets. Our validator pinpoints the exact location of syntax errors so you can fix them quickly.

Frequently Asked Questions

Is my data safe when I use this JSON formatter?

Yes. All processing happens entirely in your browser using JavaScript. Your JSON data is never sent to any server, stored, or logged.

What is the difference between JSON formatting and validation?

Validation checks whether your JSON follows correct syntax rules and reports errors. Formatting takes valid JSON and restructures it with consistent indentation for readability. Our tool does both simultaneously.

What is the maximum JSON size I can format?

Since processing happens in your browser, the limit depends on your device. Most modern browsers handle JSON files up to 50-100 MB without issues.

Why should I minify JSON?

Minification removes all unnecessary whitespace without changing the data, reducing file size by 30-60%. This is important for API responses and bandwidth-sensitive situations.

Can I use this tool for JSONL (JSON Lines) format?

This tool handles standard JSON. For JSONL, paste each line individually, or wrap lines in a JSON array with square brackets and commas between objects.

Tips

Paste JSON from API responses, config files, or package.json to format instantly.

Use Tree View to drill into deeply nested objects without losing context.

Minify before sending over the network to reduce payload size by 30-60%.

Validation errors show exact line and column numbers to help you find issues quickly.

Press Cmd+Enter to re-format the current input.