Utilities · JSON Formatter

JSON formatter and validator for Mac

Format, minify and validate JSON, with the exact line and column of any mistake.

Runs on your Mac

Get OneMacTools — $29 More Utilities tools

{"app":"OneMacTools","tools":89,"private":true,"price":{"personal":29,"pro":49}}

{
  "app": "OneMacTools",
  "tools": 89,
  "private": true,
  "price": {
    "personal": 29,
    "pro": 49
  }
}

Three steps. That's it.

1
Type or paste
Enter the text, link or details you want to use.
2
Choose the options
Set what you need in the options panel, such as action. Your choices are remembered for next time.
3
Get the result
The formatted JSON appears below your original and is copied to the clipboard.

What JSON Formatter does

Paste JSON from an API, a log or a config file to pretty-print it with 2 spaces, 4 spaces or tabs, minify it to one line, or just check it. Keys stay in their original order unless you choose to sort them, and numbers and strings are kept exactly as written. When something's wrong, you get the line and column and a plain explanation, such as a trailing comma, single quotes or a missing bracket. Nothing is sent to a website.

Options

Action: format, minify or validate onlyIndent: 2 spaces, 4 spaces or tabsSort keys A–ZAlso save as a .json file

Great for

Read a minified API response
Find the typo that breaks a config file
Shrink JSON before pasting it into a request

Questions about JSON Formatter

Does JSON Formatter upload my files?

No. JSON Formatter runs entirely on your Mac, so your files never leave it and it works offline.

Will JSON Formatter change my original files?

No. Results are saved as new files in a dated folder in Downloads › OneMacTools, and your originals are left exactly as they were unless you turn on an option that says otherwise.

What does JSON Formatter need?

Just a Mac with macOS 26 or later. There's nothing else to install.