Query String JSON Converter url
Convert URL query strings into JSON objects and JSON objects back into query strings.
What this tool does
A query string is the key=value section after the question mark in a URL, with multiple pairs joined by ampersands. It appears in address bars, API calls, logs, and redirect targets constantly, but once there are more than a handful of parameters it becomes hard to read.
This tool turns a query string into a JSON object so every key and value is visible, and assembles a query string back from JSON. Percent-encoding is handled during conversion, so encoded characters appear in readable form.
Repeated keys are represented as arrays: tags=a&tags=b becomes a tags key holding two values. Repeated keys like this are common in search filters and multi-select interfaces.
When to use it
Use it to analyse a URL loaded with tracking parameters, to move an example request from API documentation into code, to build URLs while varying parameters across test cases, or to inspect values carried in a redirect.
Input and output examples
name=alice&role=admin&page=2
{"name":"alice","role":"admin","page":"2"}
Values that look numeric are still strings in a query string.
tags=a&tags=b&q=hello%20world
{"tags":["a","b"],"q":"hello world"}
Repeated keys become an array and encoded values are decoded.
Notes and limitations
Query strings carry no type information: every value is a string, so the number 1 and the string "1" are indistinguishable, as are true and "true". When feeding converted JSON into an API body, set the types yourself. Servers also differ in how they handle repeated keys, with PHP expecting the tags[] form while other frameworks accept plain repetition.
Frequently asked questions
Numbers are converted to strings.
Query strings have no type concept, so every value is a string. Adjust types after conversion if the API requires them.
What happens with duplicate keys?
They are grouped into an array, although how a server interprets that format varies by framework.