Parses a URL query string to JSON, or builds one from JSON.
Query String to JSON converts a URL query string into a readable JSON object, and can also build a query string back from a JSON object of key/value pairs. It is handy when you are inspecting URL params, debugging API requests, or copying search parameters between tools. Everything runs in your browser, so you can paste raw query strings or JSON without sending anything anywhere.
No. The conversion runs entirely in your browser using the built-in URLSearchParams API, and nothing you paste is uploaded or stored on any server.
When a query string has the same key more than once (e.g. id=1&id=2), the values are collected into a JSON array. When converting JSON to a query string, an array value is expanded back into repeated key entries.
It is optional. A leading ? or & is stripped automatically, so both ?a=1&b=2 and a=1&b=2 work the same way.
It must be a flat JSON object of key/value pairs. Arrays as the top-level value are rejected, and non-string values are converted to strings, so nested objects become their string form rather than encoded sub-fields.
Yes. Building a query string uses URLSearchParams, so spaces and special characters are percent-encoded, and parsing decodes them back into plain text in the JSON output.