JSON Formatter & Beautifier with Auto-Correct Errors

Our online JSON Formatter is a powerful tool for developers designed to transform raw data into a structured and readable format. Unlike traditional services, it not only performs JSON Pretty Print but also features a unique automatic syntax correction feature (Auto-fix), allowing you to repair corrupted data structures with a single click.

The tool is ideal for working with API responses, configuration files, server logs, and Python or JavaScript data that requires quick validation and formatting.

Why use our JSON Prettifier?

When working with data, situations often arise where the JSON format is corrupted: missing quotes around keys, using single quotes instead of double quotes, or containing comments. Our tool solves these problems using an intelligent preprocessing algorithm.

Instant Formatting: Transforms an unreadable string into a neat tree with adjustable indentation.
Deep Validation: Doesn't just find the error, but also highlights the specific line in the editor for quick correction.
Intelligent JSON Fix: Automatically removes comments, corrects commas, and converts data types to RFC 8259.
Cross-Platform Compatibility: Correctly handles specific data types, such as Python's None or capitalized Null.

Features and Modes

1. Formatting (Beautify)

Converts minified code to a human-readable format. By default, indentation is 4 spaces, which is standard for most IDEs.

Copy
{"user":"admin","roles":["editor","viewer"],"active":true}

Result:

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{
"user": "admin",
"roles": [
"editor",
"viewer"
],
"active": true
}

2. Fix JSON syntax

This feature is indispensable when copying objects directly from JavaScript or logs. The algorithm performs the following actions:

Replaces single quotes (') with double quotes (").
Adds quotes to keys if they are missing.
Removes extra trailing commas at the end of objects and arrays.
Restores missing commas between key-value pairs.
Trims single-line (//) and multi-line (/* */) comments.

3. Minification

If you need to prepare data for network transmission or save it to a database in a minimal amount of space, use the compression mode. It removes all unnecessary spaces and line breaks.

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{"id": 1, "status": "ok"}

Special Conversion Options

The tool has switches for specific data transformation tasks:

Null to none / None to null: Allows you to quickly adapt JSON for working with Python scripts (where None is used) or return it to the JSON standard.
Remove Quotes from Keys: Useful for generating JavaScript objects where keys may not be quoted.
Wrap Keys: Forces all identifiers to be wrapped in quotes for strict conformance specifications.

Example of fixing a Python-like structure:

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{
key: 'value',
'status': None, // Comment
}

After processing with the "Fix JSON" and "None to null" options enabled:

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{
"key": "value",
"status": null
}

How to use the tool

Paste your source text into the left window (field) input).
The tool will automatically attempt to format the data (the Live Convert feature).
If there are errors in the code, they will be highlighted in red. Enable the Fix JSON checkbox to automatically fix them.
Use additional filters in the control panel to customize the output (compression, null replacement, etc.).
Click copy to get the finished result.

Frequently Asked Questions (FAQ)

Why is my JSON considered invalid?

The most common causes are: using single quotes, having comments, missing quotes around keys, or an extra comma before the closing parenthesis. Our formatter corrects these errors automatically.

Is it safe to insert sensitive data?

Yes. Data processing occurs entirely in your browser using JavaScript. Data is not sent to the server, guaranteeing complete confidentiality.

Does the service support large files?

The tool is optimized for working with texts up to several megabytes in size. Processing speed depends on the performance of your device.

What is JSONC and does the formatter work with it?

JSONC is JSON with comments. The official JSON standard doesn't support comments, but our tool can recognize them and remove them during the cleanup process (Fix JSON).

How to fix the "Unexpected token" error?

This error usually indicates a typo in the structure. Simply enable the "Fix JSON" option, and the algorithm will try to restore missing commas or fix quotation marks for you.

Conclusion

Using a professional JSON Beautifier significantly reduces the time spent debugging code and finding syntax errors. With built-in autocorrection and type conversion features, our service is an indispensable assistant for both backend developers and data scientists. Try it now and make your data clean and structured!

JSON Formatter & Beautifier with fix