Data Tools
JSON Formatter & Validator
Whether you're debugging an API response, cleaning up a config file, or just trying to read minified JSON someone pasted into a chat, a reliable JSON formatter saves real time. This free tool validates your JSON and either pretty-prints it with proper indentation or minifies it down to a single compact line, and if your JSON is invalid, it tells you where the syntax error is instead of just failing silently. It works entirely client-side, so you can format and validate JSON containing API keys or internal data structures without it touching a server.
Processed entirely in your browser — your files are never uploaded anywhere.
How to use this tool
- Paste your JSON into the left box, or upload a .json file.
- Click Format to pretty-print with 2-space indentation, or Minify to compress it onto one line.
- Copy the result or download it as a .json file.
Frequently asked questions
- What happens if my JSON is invalid?
- An error message appears below the boxes describing the problem, including the line and column where parsing failed where possible.
- Does formatting change the data?
- No — formatting only changes whitespace and indentation. The underlying keys, values, and structure are unchanged.
- What's the difference between formatting and minifying?
- Formatting adds indentation and line breaks to make JSON human-readable; minifying strips all unnecessary whitespace to make the file as small as possible for production use.
- Can this validate JSON without formatting it?
- Yes — if your JSON has a syntax error, you'll see the error message immediately when you click Format or Minify, describing exactly what's wrong.
- Is this a safe way to format JSON containing API keys or secrets?
- Yes — formatting happens entirely in your browser, so the JSON you paste is never sent to a server, unlike many online JSON formatters that process input server-side.