Developer Tool

JSON Formatter & Validator

Prettify, minify, and validate JSON instantly. Syntax-highlighted output, structure statistics, adjustable indent, and one-click copy — all in your browser with no data sent to any server.

Format & Validate JSON
Indent:
Raw JSON Input paste or type here
Formatted Output syntax highlighted
Formatted result will appear here…

How to Use

1
Paste your JSON into the left input. It can be minified, partially formatted, or even slightly broken — the tool will tell you exactly what is wrong.
2
Choose indent size — 2 spaces, 4 spaces, or tabs — from the header. The output will use your chosen style.
3
Click Format or press Ctrl+Enter. The right panel shows syntax-highlighted output with keys, strings, numbers, booleans, and nulls color-coded.
4
Use Minify to collapse the JSON into a single compact line — useful before sending in an API request or storing in a database.

Why Use This Tool

Poorly formatted JSON is hard to read and debug. This tool gives you instant visual clarity and catches syntax errors before they reach production — with a structure breakdown so you understand the shape of your data at a glance.

🎨

Syntax Highlighting

Keys, strings, numbers, booleans, and nulls are each color-coded for instant readability.

📊

Structure Stats

See total keys, arrays, nesting depth, and size at a glance before copying.

🔍

Precise Error Location

Invalid JSON shows the exact line and position of the error, not just “invalid JSON”.

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100% Private

All processing is done locally in your browser. Your JSON never leaves your machine.

What Is JSON?

JSON (JavaScript Object Notation) is a lightweight text format for storing and transporting data. It uses a key-value structure based on JavaScript object syntax, making it easy for both humans and machines to read and write.

JSON supports six data types: string, number, boolean (true/false), null, object (key-value pairs in braces), and array (ordered list in brackets). Every modern API, configuration file, and web service uses JSON as the primary data exchange format.

Frequently Asked Questions

Common JSON mistakes include: trailing commas after the last item, single quotes instead of double quotes, unquoted keys, comments (JSON does not support them), and undefined or JavaScript-only values like NaN or Infinity. The error message points to the exact position of the problem.
Format (prettify) adds indentation and newlines to make the JSON human-readable. Minify removes all unnecessary whitespace to make the JSON as compact as possible, which reduces size when transmitting over a network or storing in a database.
Yes. Valid JSON can start with an object {…} or an array […]. Both are handled correctly. You can also paste a raw primitive like "hello" or 42 — they are also valid JSON values.
No. All parsing and formatting happens in your browser using JavaScript’s built-in JSON.parse and JSON.stringify. Your data is never sent to any server.

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