JSON Formatter & Validator

About this JSON formatter

This free online JSON formatter and validator helps you clean up and verify JSON in one step. Paste your data on the left and it is validated instantly: valid JSON is beautified with your chosen indentation, while invalid JSON is flagged with the exact line and column of the first error. You can switch the output between a formatted text view and an interactive collapsible tree to explore deeply nested structures.

Everything happens locally in your browser — nothing is uploaded — so it is safe to use with sensitive payloads such as API responses, webhook bodies, and configuration files.

How to format JSON

1. Paste your JSON into the input box.
2. Choose your indentation (2 spaces, 4 spaces, or tabs) and the formatted result appears instantly.
3. Press Minify to compress it, or switch to the Tree view to browse the structure.
4. Click Copy to grab the result.

Frequently asked questions

Is my JSON data uploaded to a server?

No. This formatter runs entirely in your browser using JavaScript. Your JSON never leaves your device, which makes it safe for API responses, tokens, and private config files.

Why does it show the exact line and column of an error?

When JSON is invalid, the validator reports the precise line and column of the first problem so you can jump straight to it — instead of a vague 'unexpected token' message.

What does “Fix trailing commas” do?

Trailing commas (a comma before a closing } or ]) are valid in JavaScript but not in JSON, and they are a very common cause of parse errors. The fix button removes them so the JSON parses.

What is the difference between formatting and minifying?

Formatting (beautifying) adds indentation and line breaks to make JSON readable. Minifying strips all unnecessary whitespace to make the payload as small as possible for storage or transport.

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