Effloow / Tools / JSON Formatter
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JSON Formatter & Validator

Paste your JSON to instantly format, validate, minify, or explore it as a tree. Everything runs in your browser — nothing is sent to any server.

Input JSON

0 B

Formatted Output

Formatted JSON will appear here

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Keys

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Max Depth

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Arrays

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Formatted Size

Frequently Asked Questions

What is JSON?
JSON (JavaScript Object Notation) is a lightweight data interchange format. It is easy for humans to read and write, and easy for machines to parse and generate. JSON is the most common format for APIs, configuration files, and data storage on the web.
Is my JSON data stored or sent anywhere?
No. All formatting and validation runs entirely in your browser using JavaScript. Your data never leaves your device — nothing is sent to any server or third-party service. You can even use this tool offline once the page is loaded.
What types of JSON errors can this tool detect?
This tool detects all JSON syntax errors including missing commas, unmatched brackets or braces, invalid strings, trailing commas, single quotes instead of double quotes, comments (not allowed in standard JSON), and more. Error messages include the approximate line and character position of the error.
What is the maximum JSON size this tool can handle?
Since everything runs in your browser, the limit depends on your device's available memory. In practice, this tool handles JSON files up to several megabytes without issues. For very large files (10MB+), formatting may take a moment.