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JSON Formatter

Beautify, validate and explore JSON in one place. Free

InputWaiting for JSON

Output




Formatted JSON appears here as soon as your input is valid.




Ready









Size
0 B
1 line


Keys
0
0 values


Max depth
0
levels of nesting


Objects
0
0 arrays









About the JSON Formatter & Validator


Whisser JSON Formatter turns messy or minified JSON into clean, readable code and tells you exactly where it breaks when it is invalid. Format with 2 spaces, 4 spaces or tabs, minify for production, sort keys, and explore deeply nested API responses in a collapsible tree. Everything runs in your browser, so your data stays private.


How to use


  1. Paste JSON into the input, drop a .json file on it, or click Sample to try it out.
  2. Watch the status: valid JSON is formatted on the right as you type, and errors show the exact line and column.
  3. Choose 2 spaces, 4 spaces or Tab, switch on Sort keys, or click Minify for a compact version.
  4. Switch to Tree to explore nested data, and click any key to copy its JSONPath.
  5. Copy the result or download it as a .json file.


Frequently asked questions


What does a JSON formatter do?
A JSON formatter adds consistent indentation and line breaks to JSON so it is easy to read. Whisser JSON Formatter can also minify JSON to a single line, sort object keys alphabetically and show the data as a collapsible tree.


How do I find an error in my JSON?
Paste your JSON and the validator checks it as you type. If it is invalid, you see a short explanation with the line and column of the problem, the line is highlighted in the editor, and Go to error moves your cursor there.


What are the most common JSON mistakes?
Trailing commas after the last item, single quotes instead of double quotes, property names without quotes, comments, and missing commas between items. JSON also does not allow values such as undefined or NaN.


Is my JSON uploaded to a server?
No. Parsing, formatting and validation all run in your browser with JavaScript, so your data never leaves your device. That makes it safe for API responses and configuration files.


How large a JSON file can I format?
Files up to about 10 MB open fine in most browsers. For very large output, syntax colors are turned off to keep the page fast, and the tree view loads nested items as you expand them.


Is the JSON formatter free?
Yes. It is free to use and does not require an account.