URL Query String Parser
A query string is the portion of a URL that follows the '?' character, consisting of key=value pairs separated by '&'. This tool uses the browser's built-in URLSearchParams API to parse any URL or raw query string, automatically handling percent-encoding so you see the fully decoded parameter names and values in a clear table.
You can also work in reverse: add as many key/value rows as you need and the tool will instantly build a properly encoded query string ready to append to any URL. This is invaluable when debugging API requests, constructing redirect links, or inspecting tracking parameters in marketing URLs.
How it works
Parsing: extract the portion after '?' then split on '&'; each segment is split on the first '=' to give key and value, both decoded via decodeURIComponent(). Building: use URLSearchParams.append(key, value) for each row, then prefix the result with '?'.
Use cases
- Debugging REST API requests by inspecting URL parameters
- Analyzing UTM tracking parameters in marketing campaign links
- Building redirect or callback URLs with dynamic query strings
- Decoding percent-encoded values from browser address bars
- Testing query string handling in web application development