JSON Formatter & Validator
Format, validate, and beautify JSON data instantly. Paste messy JSON and get clean, indented output.
Clean up API responses, config files, and pasted JSON snippets without installing an editor plugin. This formatter makes nested data easier to scan, validates syntax, and can compact JSON again when you need a smaller payload.
How to use JSON Formatter & Validator
- Paste your JSON object, array, or API response into the input editor.
- Use the format action to apply readable indentation, or minify when you need compact JSON.
- Review validation feedback before copying the cleaned output into your app, docs, or test fixture.
Features
- Formats nested objects and arrays into readable indentation.
- Validates JSON syntax so missing commas, quotes, or brackets are easier to catch.
- Supports both pretty printed output and compact minified JSON.
- Works well for API debugging, frontend fixtures, configuration files, and webhook payloads.
Examples
Beautify an API response
{"user":{"id":42,"roles":["admin","editor"]},"active":true}{
"user": {
"id": 42,
"roles": [
"admin",
"editor"
]
},
"active": true
}Minify JSON for transport
{
"status": "ok",
"count": 3
}{"status":"ok","count":3}Privacy
Your JSON stays in the browser. Avoid pasting production secrets into any online tool unless your team policy allows it.
FAQ
Is this JSON formatter private?
Yes. Formatting and validation run in your browser, so pasted JSON is not uploaded to FreeToolJet.
Can it fix invalid JSON automatically?
It reports syntax problems, but you should correct invalid JSON intentionally so data is not changed in unexpected ways.
What is the difference between formatting and minifying JSON?
Formatting adds indentation and line breaks for readability. Minifying removes extra whitespace to make the JSON string smaller.