JSON ⇄ Query String

Array values are encoded as a repeated key — {"tag":["a","b"]} becomes tag=a&tag=b — and repeated keys parse back into an array.

Why Convert Between JSON and Query Strings?

URL query strings and JSON objects represent the same key-value data in different formats. This tool converts a JSON object into a properly percent-encoded query string, or parses an existing query string back into JSON — grouping repeated keys into arrays.

Features

  • Correct encoding — uses URLSearchParams for proper percent-encoding of spaces and special characters.
  • Array support — array values become repeated keys and parse back into arrays automatically.
  • Two-way conversion — JSON to query string, or query string to JSON.

Common Use Cases

  • Building a query string from a JSON filter/search state object.
  • Debugging what an existing URL's query parameters actually decode to.
  • Converting form state to and from shareable URLs.

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