Is my JSON sent to your servers?

No. Formatting and validation run entirely in your browser. It is safe to paste JSON containing API keys, tokens, or any other sensitive data — nothing leaves your machine.

What is the maximum file size the tool can handle?

Files up to 5 MB format quickly. Larger files may take a moment depending on your device; if you regularly work with very large JSON, splitting it into logical sections is a good practice.

Does the tool validate JSON or just format it?

Both. Valid JSON is formatted and returned; invalid JSON triggers an error message with the line and character position of the problem so you can fix it.

Will formatting change any of my data values?

No. The tool only adjusts whitespace and indentation. Keys, values, data types, and object order are preserved exactly as provided.

Does it support JSON5 or JSON with comments?

Standard JSON only. JSON5 files or files with trailing commas and comments need to be converted to valid JSON first — remove comments and trailing commas before pasting.

Can I use it on a phone or tablet?

Yes, it works in mobile browsers. For editing large files, a desktop browser provides a more comfortable experience with better keyboard support.

Is there any cost or account required?

The tool is completely free. No account, no subscription, and no usage limit.

JSON formatter — Free Online

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Input (JSON)256 bytes

Output

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📖 How to Use

Upload document

Drag-drop or pick file.

Set options

Choose operation and parameters.

Process

Server runs the task.

Download

Get result in your format.

JSON Formatter

📖 How to Use