JSON Formatter

Tidy up and check JSON

Make JSON readable, or find the line that breaks it.

Paste your JSON

JSON

Copy the result

This all happens on your device. Nothing you type or add is sent anywhere. Check it yourself

Is my JSON sent anywhere?

No. It's parsed in this tab, and the page's security policy blocks it from sending data anywhere. That makes it safe for API keys and customer data.

Why does it say my JSON is invalid?

The most common causes are a trailing comma, single quotes instead of double quotes, or a missing closing bracket. The error shows the line and column to look at.

About this tool

Runs	In your browser. Your files stay on your device.
Engine	Your browser's own JSON parser
Options	2 or 4 spaces, tabs, minified; sort keys
Works offline	Yes, once the page has loaded
Licence	AGPL-3.0
Added	27 September 2026
Built by	Sapience Design
Source	tools/data/json-formatter

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Tidy up and check JSON

Paste your JSON

Tidy or shrink?

Copy the result

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