JSON Formatter & Validator
Paste JSON to pretty-print, validate, or minify it. Syntax highlighting, error detection with line numbers, and one-click copy.
How It Works
Paste your JSON
Paste your JSON into the input area or load a sample to get started.
Format or minify
Choose 2-space or 4-space indentation for pretty-printing, or minify to remove all whitespace.
Copy the result
Copy the formatted output to your clipboard with one click. Any syntax errors are highlighted with line numbers.
Frequently Asked Questions
Does this tool validate JSON?
Yes. If your JSON has syntax errors, the tool highlights the exact line and character position where the error occurs.
Is my data sent to a server?
No. All formatting and validation happens entirely in your browser. Your data never leaves your device.
What indentation options are available?
You can format with 2-space or 4-space indentation, or minify the JSON to remove all unnecessary whitespace.
Does it show the size difference after formatting?
Yes. The tool displays the input and output sizes in bytes so you can see exactly how much space formatting or minifying adds or removes.