How to use the JSON formatter
- Paste your JSON into the input box, or type it directly.
- Click Format to pretty-print with two-space indentation, Validate to check syntax only, or Minify to compress it to a single line.
- Read the status row — valid JSON shows a summary, while invalid JSON shows the error message and character position.
- Copy the formatted output straight from the result block for use in your code or config files.
Why validate JSON before using it
JSON (JavaScript Object Notation) is the data format that powers most modern APIs, configuration files and browser storage. A single missing comma, trailing comma or unquoted key can break an entire application, and the resulting error is often reported far away from the actual mistake. Validating your JSON before pasting it into a program or sending it to an API saves you from puzzling over cryptic failures.
When you click Validate, this tool parses the input with the browser's own JSON parser. If the parse succeeds, it reports the top-level type — whether you have an object, an array, or a plain value — and, for objects and arrays, how many keys or items it contains. If it fails, the error message includes the exact character position where parsing stopped, which is usually the spot you need to fix.
Formatting vs minifying
| Action | What it does |
|---|---|
| Format | Re-indents the JSON with two spaces per level so nested objects and arrays are easy to read. |
| Validate | Checks the syntax without changing anything, and reports the data type and size. |
| Minify | Removes all whitespace so the JSON is as small as possible — useful before embedding it in a URL or saving space. |
When this tool comes in handy
Developers format API responses to inspect their structure before writing parsing code. Data analysts clean up exported JSON before importing it into another tool. Anyone debugging a web app can paste a broken payload here to find the offending character in seconds instead of scanning by eye.