JSON Formatter, Validator & Minifier

Paste messy or minified JSON — beautify it, minify it, or check it's valid, entirely in your browser.

{"name":"Jordan Lee","role":"Developer","skills":["JavaScript","CSS","HTML"],"active":true,"projects":3}

How this tool works

This tool uses your browser's built-in JSON.parse() and JSON.stringify() functions — the same JSON engine every modern browser and most JavaScript environments rely on — so the validation you get is exactly what any real application would encounter, not a simplified approximation. "Beautify" re-serializes your JSON with 2-space indentation for readability; "Minify" strips all unnecessary whitespace to produce the smallest possible payload size, which matters for things like API responses or config files where every byte counts.

When your JSON is invalid, the error message comes directly from the parser and typically points to roughly where the problem is — a missing comma, an unclosed bracket, or a stray trailing comma (which is valid in JavaScript object literals but not in strict JSON).

Frequently asked questions

Why does my JSON fail validation even though it looks correct?
The most common culprits are trailing commas (like {"a":1,}), single quotes instead of double quotes around keys and strings, or unquoted keys — all valid in JavaScript object syntax, but not in strict JSON.

What's the difference between JSON and a JavaScript object?
JSON is a stricter text-based data format: all keys and string values must use double quotes, trailing commas aren't allowed, and functions/comments can't be included. A JavaScript object literal is more permissive syntax that JSON borrowed from.

Is my data safe to paste here if it's sensitive?
Yes — parsing, formatting, and minifying all happen locally in your browser using built-in JavaScript functions. Nothing is uploaded or transmitted to any server.

Why would I want to minify JSON at all?
Smaller file size — useful for reducing bandwidth in API responses, config files bundled into an app, or anywhere storage or transfer size actually matters. For human-edited config files, beautified (readable) JSON is usually better.

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