Paste a flat JSON object, and the tool converts it into a URL-encoded query string, repeating keys for array values.
An array value is expanded into repeated key=value pairs, for example {"t":["a","b"]} becomes t=a&t=b, which most servers parse back into a list.
Yes. Keys and values are passed through encodeURIComponent, so spaces, ampersands and other reserved characters are safely percent-encoded.
Nested object values are serialized to JSON and encoded as a single value. For best results provide a flat object of simple key-value pairs.