JSONKit Formatter — Every Feature Explained
JSONKit's JSON Formatter is more than a simple beautifier. Here is a complete guide to every feature and when to use it.
Live Validation as You Type
As soon as you start pasting or typing JSON, the formatter validates it in real time. You do not need to click any button. If your JSON has a syntax error, a red error bar appears at the bottom of the input panel showing the exact line number and column where the problem is.
Format and Beautify
Click the Format button or press Ctrl + Enter on Windows or Cmd + Enter on Mac. You can choose between 2-space, 3-space and 4-space indentation using the segment control in the toolbar.
Minify
Click Minify to strip all whitespace and compress your JSON to the smallest possible size. Minification typically reduces JSON size by 20 to 40 percent.
Sort Keys
Click Sort Keys to sort all object keys alphabetically at every level of nesting. Key sorting is recursive — every nested object is sorted, not just the top level.
Indentation Control
The 2 / 3 / 4 tab selector controls how many spaces are used for each indent level. Changing it while formatted output is already showing immediately reformats the output.
Upload a File
Click Upload to open a file picker and load a local JSON file directly into the editor. Supported file types are .json and .txt. Processing happens in your browser — nothing is uploaded to a server.
Download Output
Click Download to save the formatted or minified JSON as a file named output.json.
Copy to Clipboard
Click Copy in the output panel header to copy the entire output to your clipboard in one click. The button briefly shows Copied to confirm.
Split, Input and Output Views
The view switcher has three modes. Split shows both panels side by side. Input expands the input panel to full width. Output expands the output panel to full width for reading large results.
Session Auto-Save
Your last input is automatically saved to localStorage. If you close the tab or refresh the page, your JSON is still there when you come back. Click Clear to wipe the session.
Status Bar
The dark status bar at the bottom shows: whether the JSON is valid or has an error, the input file size, the number of lines in the output, and the current indentation setting.