{ } JSON Formatter
Beautify, validate & minify JSON instantly. Explore structure with interactive tree view, see type stats, and download — free, 100% private, no login required.
Paste JSON above to format, validate & explore
Works with any JSON — API responses, config files, data exports. Get syntax highlighting, interactive tree view, and size stats instantly.
Everything You Need to Work with JSON
Format, validate, explore, and compress — the complete JSON toolkit for developers and data wranglers.
Instant Formatting
Click Format to beautify any JSON instantly with proper indentation and line breaks.
Validation with Error Line
Invalid JSON shows the exact error message and line number so you can fix it immediately.
Minify & Compress
Strip all whitespace for the smallest possible JSON — see exactly how much space you save.
Interactive Tree View
Explore nested JSON as a collapsible tree — expand and collapse objects and arrays at any depth.
Syntax Highlighting
Color-coded output: keys in blue, strings in light-blue, numbers in orange, booleans in red, null in gray.
Sort Keys
Sort all object keys alphabetically — recursively applied to every nested object.
Structure Stats
See total keys, max nesting depth, value count, and a type breakdown chart for every JSON.
Size Comparison
Visual bar chart comparing formatted vs minified size with percentage savings.
100% Private
All processing is client-side — your JSON never leaves your browser.
Who Uses This JSON Formatter?
Frontend and backend developers, DevOps engineers, data analysts, and anyone who works with JSON data.
API Response Debugging
Paste raw API responses to instantly see the structure and find the exact field you need.
Config File Editing
Format package.json, tsconfig.json, or any configuration file for easier reading and editing.
API Development
Validate and format JSON request bodies before sending them to your API.
Database Exports
Format JSON exports from MongoDB, PostgreSQL JSON columns, or Firebase.
Learning JSON
Load the sample JSON to explore the structure with the tree view and understand all 6 data types.
Minify for Production
Compress config or data files for production builds to reduce bandwidth and load times.
Frequently Asked Questions
Everything about JSON formatting, validation, minification, and how to fix common JSON errors.
What is a JSON formatter?
A JSON formatter (also called a JSON beautifier or pretty printer) takes minified or poorly indented JSON and formats it with consistent indentation, making it easy to read and understand. It also validates the JSON syntax and reports any errors. JSON formatters are essential tools for developers working with APIs, config files, and data exports.
How do I format JSON online?
Paste your JSON into the input box above and click the '✨ Format' button. The tool will validate, parse, and re-format the JSON with proper indentation. You can choose 2 or 4 space indentation and optionally sort keys alphabetically. The result appears with syntax highlighting below. Click 'Copy' to copy it to your clipboard, or 'Download' to save it as a .json file.
What is JSON validation?
JSON validation checks whether your text conforms to the JSON specification (RFC 8259). Common JSON errors include: missing or extra commas, unquoted property names, single quotes instead of double quotes, trailing commas, undefined or NaN values, and unmatched brackets. This tool validates as you type and shows the exact error message and line number when invalid JSON is detected.
What is JSON minification?
JSON minification removes all unnecessary whitespace (spaces, newlines, indentation) from JSON, resulting in the smallest possible file size. Minified JSON is harder to read but faster to transfer over networks. It's used for API responses, data storage, and reducing bandwidth. This tool shows you exactly how much space you save by minifying (typically 20-60% for heavily formatted JSON).
What is the JSON tree view?
The tree view displays JSON as an interactive, collapsible hierarchy. Click any object {} or array [] to expand or collapse it. This makes it easy to navigate complex nested JSON without scrolling through hundreds of lines of text. The tree view is particularly useful for large API responses or deeply nested configuration objects.
What does 'Sort keys' do?
When 'Sort keys' is enabled, all object property keys are sorted alphabetically before formatting. This makes it easier to compare two JSON objects or find a specific key quickly. Sorting is applied recursively to all nested objects. Note that JSON objects are technically unordered by the spec, so key order should not affect functionality.
What are the JSON data types?
JSON supports 6 data types: String (text in double quotes, e.g. "hello"), Number (integer or decimal, e.g. 42 or 3.14), Boolean (true or false), Null (empty value: null), Object (key-value pairs in curly braces: {"key": value}), and Array (ordered list in square brackets: [1, 2, 3]). This tool shows a breakdown of how many of each type appear in your JSON.
What is the difference between JSON and JavaScript objects?
JSON (JavaScript Object Notation) is a text format, while a JavaScript object is a runtime data structure. Key differences: JSON requires double quotes around property names (not optional like in JS), JSON does not support undefined, functions, Date objects, or comments, and JSON strictly defines 6 data types. JavaScript's JSON.parse() converts JSON text to objects, and JSON.stringify() converts objects back to JSON text.
Why do I get a 'Unexpected token' JSON error?
The most common causes of 'Unexpected token' errors in JSON: (1) Single quotes used instead of double quotes — JSON requires ", not '. (2) Trailing comma after the last item in an array or object — not allowed in JSON. (3) Unquoted property names — every key must be in double quotes. (4) JavaScript values like undefined, NaN, or Infinity — not valid JSON. (5) Comments — JSON does not support // or /* */ comments. Paste your JSON here to see the exact error and line number.
Is it safe to paste my JSON here?
Completely safe. All processing happens in your browser using JavaScript — no JSON data is ever sent to any server. You can safely paste API keys, user data, or confidential configuration files. The page works offline once loaded and never stores or logs any input.
How large a JSON file can this tool handle?
The tool can parse and format JSON files of any size that your browser can handle in memory. Syntax highlighting is enabled for files up to 120 KB; larger files are displayed as plain text for performance. The interactive tree view is limited to the first 5,000 nodes to prevent browser slowdown. For most JSON files from APIs, logs, and configs, there are no practical limits.
What does the 'max depth' stat mean?
Max depth (also called nesting depth) is the deepest level of object/array nesting in your JSON. A flat JSON like {"a": 1} has depth 1. A JSON with a nested object like {"user": {"address": {"city": "London"}}} has depth 3. Very high nesting depths (10+) can indicate complex data structures that may be difficult to work with. The tree view is particularly helpful for navigating deeply nested JSON.