JSON Formatter
Free online JSON formatter and beautifier. Paste or upload JSON to instantly format with proper indentation, minify for production, browse with collapsible tree view, and analyze structure with stats. Supports Auto-Fix for trailing commas, single quotes, and unquoted keys.
How to Use
Paste raw JSON directly into the input editor, or click "Upload" to load a .json file from your computer.
Hit "Format" to beautify with readable indentation, or "Minify" to compress it into a single line for production use. Choose 2 or 4 space indentation.
Switch to "Tree View" to visually browse nested objects and arrays. Use "Stats" to see a breakdown of objects, arrays, keys, strings, depth, and file size.
Click "Copy" to copy the formatted JSON to your clipboard, or "Download" to save it as a .json file ready for use in your project.
What Is a JSON Formatter?
A JSON formatter (also called a JSON beautifier or JSON pretty printer) takes raw, compressed, or poorly formatted JSON and reformats it with proper indentation, line breaks, and spacing. The result is human-readable JSON that's much easier to read, debug, and share. This tool also supports minification — removing all whitespace to produce compact JSON optimal for APIs and production environments.
When Should You Use a JSON Formatter?
- Debugging API responses — API responses are often minified. Pasting them into the formatter instantly gives you readable, indented JSON to find the data you need.
- Code review and documentation — Properly indented JSON is much easier to read in code reviews, README files, and internal documentation.
- Config file editing — Configuration files like
package.json,tsconfig.json, andappsettings.jsonare JSON. Keeping them well-formatted prevents accidental syntax errors. - Minifying for production — Removing whitespace reduces the file size of JSON payloads, improving API response times and reducing bandwidth usage.
Tree View: Visual JSON Browsing
The Tree View tab renders your JSON as a collapsible tree. Click the arrow next to any object or array to expand or collapse it. This is especially useful for deeply nested JSON — you can fold sections you don't need and focus only on the part of the structure you're working with. Each node shows the number of keys or items it contains when collapsed.
Stats: JSON Structure Analysis
The Stats tab shows a full breakdown of your JSON: total objects, arrays, string values, numbers, booleans, null values, total keys, maximum nesting depth, and file size. This is helpful when analyzing large or complex JSON structures — for example, to understand the shape of an API response before writing code to process it.
Auto-Fix: Recovering Invalid JSON
The Auto-Fix button attempts to repair common JSON mistakes automatically. It fixes trailing commas (which are valid in JavaScript but not JSON), converts single-quoted strings to double-quoted, adds missing double quotes around unquoted property keys, and replaces undefined values with null. After fixing, the corrected JSON is written back to the input so you can see exactly what was changed.
Privacy
All formatting, validation, and analysis happens entirely in your browser using JavaScript. Your JSON data is never sent to any server, stored, or shared. You can safely format sensitive data like API keys, private config files, or customer records.
Frequently Asked Questions
A JSON formatter reformats raw or minified JSON into a human-readable structure with proper indentation and line breaks. You need one when working with API responses (which are usually minified), debugging configuration files, reviewing data structures, or preparing JSON for documentation.
Format (Beautify) adds indentation and line breaks to make JSON human-readable — ideal for development, debugging, and documentation. Minify removes all whitespace to compress JSON into a single line — ideal for APIs, storage, and production environments where smaller payload size matters.
No. Formatting only changes the whitespace — indentation, line breaks, and spacing. All keys, values, data types, and nesting remain exactly the same. A formatted and a minified version of the same JSON are semantically identical and will parse to the same object.
Auto-Fix handles the most common JSON mistakes: trailing commas before } or ] (valid in JS but invalid in JSON), single-quoted strings instead of double-quoted, unquoted property keys (like in JavaScript object literals), and undefined values (replaced with null). Complex structural errors like unclosed brackets may require manual correction.
Yes. Click the "Upload" button and select any .json or .txt file from your computer. The file contents will be loaded into the editor and automatically formatted. The file never leaves your browser — it is read locally using the FileReader API.
Completely. All processing happens in your browser using JavaScript. Your JSON is never transmitted to any server, logged, stored, or shared. You can safely use this tool with sensitive data including API credentials, private configuration, and personal records.
There is no hard limit. The tool can handle JSON files of any size, as everything is processed locally in your browser. Very large files (several MB) may take a moment to format, but will complete successfully depending on your device's available memory.