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Data Formatting

JSON Formatter & Validator — Beautify, Minify, Sort

Paste any JSON to beautify (pretty-print), minify, validate syntax, or sort keys alphabetically. Everything runs locally in your browser — your data is never uploaded anywhere.

🧩 JSON Formatter

Input JSON
Output
Output will appear here...
Privacy: All processing happens client-side using your browser's built-in JSON.parse — nothing is sent to our servers.
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Privacy note: This tool runs entirely in your browser. Your JSON data is never uploaded, logged, or transmitted to SmartUtilz or any third party — safe to use with API responses, config files, or other sensitive data.

How JSON Formatting Works

JSON (JavaScript Object Notation) is the universal data exchange format for web APIs, configuration files, and modern databases. This tool uses your browser's native JSON.parse() and JSON.stringify() functions to parse, validate, and re-serialize your data:

Step-by-Step Worked Example

Suppose you paste this minified, hard-to-read API response:

{"name":"SmartUtilz","tools":30,"free":true,"categories":["finance","health","dev"]}

Clicking Beautify re-indents it to:

{ "name": "SmartUtilz", "tools": 30, "free": true, "categories": [ "finance", "health", "dev" ] }

The stats panel also shows this JSON has 7 total keys/values tracked recursively (including array items), an original size, and how much smaller the minified version is — useful for judging API payload efficiency.

Common JSON Syntax Errors

ErrorExample (invalid)Fix
Trailing comma{"a":1,}{"a":1}
Unquoted key{a:1}{"a":1}
Single-quoted string{'a':'b'}{"a":"b"}
Mismatched brackets{"a":[1,2}{"a":[1,2]}
Comment (not valid JSON){"a":1 // note}Remove the comment

Frequently Asked Questions

A JSON formatter (also called a JSON beautifier or pretty-printer) takes raw JSON text — often minified or copied from an API response — and re-indents it with consistent spacing and line breaks so nested objects and arrays are easy to read. It can also minify JSON (strip all whitespace to reduce size), validate that the JSON is syntactically correct, and sort object keys alphabetically.
The most common errors are: trailing commas after the last item in an object or array (valid in JavaScript object literals but not in strict JSON), unquoted or single-quoted keys (JSON requires double-quoted keys), missing or mismatched brackets/braces, and using undefined, functions, or comments — none of which are valid JSON. This tool's Validate button pinpoints the exact error and position.
No. All formatting, validation, and minification happens entirely in your browser using JavaScript's built-in JSON.parse and JSON.stringify — your data is never sent to SmartUtilz's servers or any third party, which makes this safe to use even with sensitive API responses or configuration files.
Beautify (pretty-print) adds indentation and line breaks to make JSON human-readable for debugging or code review. Minify strips all unnecessary whitespace to produce the smallest possible file size, which is what you'd want for production API responses or config files where every byte of transfer size matters.
Sorting keys makes two JSON structures directly diffable — for example, comparing an API response against an expected schema, or spotting drift between two config files that should be identical. It's also commonly used before committing JSON files to version control, since a consistent key order produces cleaner git diffs.