Free · No signup · Runs entirely in your browser
JSON Formatter
Paste JSON and format, validate or minify it. Parsing and formatting happen entirely locally in your browser — nothing you paste is sent anywhere.
How it works
- Paste or type JSON into the input box.
- Pick an indent width, then click Format to pretty-print it, or Minify to compact it.
- Invalid JSON shows a friendly error with the exact line and column.
- Copy the result when you're happy with it.
Frequently asked questions
What is JSON formatting?
JSON formatting (also called pretty-printing) adds line breaks and indentation to compact JSON so nested objects and arrays are easy to read. This tool can also do the opposite — minify formatted JSON back down to a single compact line.
Does it validate my JSON?
Yes. Every format or minify attempt parses your input first. If it isn't valid JSON, you'll see a friendly error with the exact line and column where parsing failed instead of a formatted result.
Is anything I paste uploaded anywhere?
No. Formatting, validating and minifying all happen locally in your browser using JavaScript — nothing you paste is sent to a server.
What indent options are available?
You can choose 2 spaces, 4 spaces, or a tab character for the output indentation. Minify ignores the indent setting and always produces the most compact single-line output.
Does it handle large JSON files?
Yes — since parsing and formatting run entirely in your browser's own JavaScript engine, there's no upload size limit or server timeout. Very large documents are only limited by your device's memory.