How to use it
Paste JSON into the top box and press Format (or Ctrl/⌘ + Enter). Valid JSON is re-indented with 2 spaces, 4 spaces or tabs; Minify removes all whitespace for the smallest payload. Tick “sort keys” to order object keys alphabetically, which makes two JSON files easier to compare.
If the JSON is invalid, the page shows the parser message with the line and column and selects the spot in the input. The usual culprits are a trailing comma after the last item, single quotes, unquoted keys and comments, none of which are allowed in standard JSON.
Parsing uses your browser’s built-in JSON.parse, so the data never leaves your computer. That matters for API keys, customer records and configuration files.