When you copy an API payload out of documentation you often have a JSON object, but Postman wants it as key-value rows in its Params or Body table. This tool flattens a JSON object into three interchangeable formats: a plain "key : value" table you can paste row by row, an x-www-form-urlencoded string (key=value&key=value, percent-encoded), or a URL query string prefixed with ?. Non-string values are JSON-encoded so numbers, booleans, arrays and nested objects survive the round trip.
The reverse direction parses any of those three formats back into a formatted JSON object, decoding percent-escapes and re-parsing values that look like numbers, booleans or JSON. Everything runs locally in your browser using the native URLSearchParams and JSON parsers — your request data is never uploaded.