Query String Parser & Builder
The Query String Parser & Builder decodes any URL or query string into readable key-value pairs, shows them as a table and as JSON, and rebuilds a normalised, correctly percent-encoded query string.
100% in-browser · no data sent
It handles plus-encoded spaces, repeated keys, empty values and URL fragments.
Embed This Tool
Add this tool to your website with customizable styling
How to Use
Paste a URL or query string
Paste a full URL, a bare query string such as ?a=1&b=2, or just a=1&b=2. Everything is parsed automatically as you type.
Read the parsed parameters
Each parameter is decoded and listed in a table with its key and value, so you can see exactly what the URL is passing.
Copy the JSON or query
Copy the parameters as a JSON object, or copy the rebuilt query string and full URL with all values correctly encoded.
Edit and re-parse
Change the input and the table, JSON and rebuilt query update instantly — handy for cleaning up or comparing URLs.
Frequently Asked Questions
What is a query string?
A query string is the part of a URL after the ? that carries parameters as key=value pairs separated by &, for example ?q=shoes&page=2. This tool splits it apart and decodes each value for you.
Does it decode URL-encoded values?
Yes. Percent-encoded characters such as %20 are decoded, and a + is treated as a space, so hello%20world and hello+world both become “hello world”. Malformed escapes are left as-is instead of causing an error.
How are repeated parameters handled?
Repeated keys like ?tag=a&tag=b are kept as separate rows in the table, and collapse into an array in the JSON output (for example { "tag": ["a", "b"] }) so no values are lost.
Is my data sent anywhere?
No. All parsing and encoding happens entirely in your browser using JavaScript. Nothing you paste is uploaded or stored on any server, so it is safe to use with URLs that contain tokens or personal data.