JSON Formatter
Beautify, minify and find errors by line.
This file is larger than 10 MB; formatting may be slow on this device.
Your data never leaves your device — everything runs in your browser.
How to use it
- Paste or type your JSON into the input box.
- Choose the indentation: 2 spaces, 4 spaces or Tab.
- Press Beautify to format it, or Minify to put everything on one line. The JSON is checked as you type.
- If the JSON is invalid, go to the line and column shown in the error message and fix it.
- Press Copy to put the result on your clipboard.
Frequently asked questions
What does a JSON formatter do?
It adds line breaks and indentation so nested objects and arrays are easy to read. The data itself does not change, only how it is laid out. This makes API responses, config files and logs much easier to scan and debug. Minify does the opposite: it removes every space and line break outside strings, for the smallest size.
Why is my JSON invalid?
The most common causes are a trailing comma after the last item, single quotes instead of double quotes, keys without quotes, and comments (JSON does not allow them). The error message points to the line and column where the parser stopped.
Why did a number in my JSON change?
Numbers are read as standard JavaScript numbers, the same way browsers and most APIs read them. So 1.0 is shown as 1, and whole numbers longer than about 15–16 digits (above 9,007,199,254,740,991) can lose their last digits. Keep very long IDs as strings in quotes to be safe.
Can I use it as a JSON validator?
Yes. Paste your JSON: if it is invalid, you see the line and column of the first error.
Is my data sent to a server?
No. Formatting and validation happen entirely in your browser, and your JSON never leaves your device. That makes it safe to check data that contains tokens or personal information.