Query String Converter Online — Query Parameters to JSON
Convert URL query strings to JSON or JSON objects to encoded query strings locally.
About this tool
URLSearchParams parses repeated keys into arrays. JSON input supports scalar and array values and encodes them into parameters.
How to use
- Enter or select the required input.
- Run the tool with the intended options.
- Review the result before using or downloading it.
Features
- Two-way query/JSON conversion.
- Repeated-key arrays.
- Percent encoding through URLSearchParams.
Common use cases
- Debug API URLs.
- Build request parameters.
- Inspect tracking queries.
Common issues and tips
- Nested JSON objects become string values.
- A leading question mark is optional.
Privacy
Processing runs locally in your browser. Input is not uploaded to Tools12345.
Frequently asked questions
Are repeated keys preserved?
Yes, they become arrays.
Is the question mark required?
No.
Are values typed?
Parsed query values are strings.