Query String to JSON

Convert a URL query string into readable JSON, inspect repeated parameters, choose value types, and copy or download the result locally.

🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.

Query string workspace

Paste parameters or a complete URL. Parsing stays in this browser tab.

Convert true, false, null, and numbers into JSON values

6 parameters parsed from the example.

Query string or URL

Leading ? is optional. For a full URL, only the part after ? is used.

JSON result

{
  "utm_source": "newsletter",
  "utm_campaign": "summer-sale",
  "featured": true,
  "limit": 24,
  "tag": [
    "tools",
    "privacy"
  ]
}

5 unique keys; repeated keys are kept as arrays.

Paste URL parameters such as source=newsletter&limit=24, or paste a complete URL.
The browser separates and decodes each key/value pair, retaining repeated keys in an array.
Choose whether common numbers, booleans, and null values become JSON types, then copy or download the result.

Each parameter becomes one JSON property. A property seen once gets a single value; a property seen again becomes an array so no input is lost.

tag=tools&tag=privacy → { "tag": ["tools", "privacy"] }

Does the URL or query string get uploaded?

No. Your input is parsed locally with the browser URLSearchParams API and is never sent to a server.

What happens when a key appears more than once?

Repeated keys are preserved as an array. For example, tag=tools&tag=privacy becomes "tag": ["tools", "privacy"].

Can I paste a complete URL?

Yes. The tool uses the query portion after the question mark and ignores the rest of the URL.

Why are numbers and true/false values not strings?

The conversion option is enabled by default so common JSON values are useful immediately. Turn it off to keep every value as text.

Feature	Online Tool Store	Browser console	Manual editing
No upload or sign-up	Yes	Yes	Yes
Repeated keys become arrays	Automatic	Manual code	Manual
Copy and download JSON	Included	Manual	Manual

If you need a quick readable conversion without opening developer tools or writing parsing code, Query String to JSON is the direct path.