Query String Converter
Convert URL query parameters and flat JSON objects in either direction while preserving repeated values.
This tool runs entirely in your browser. Your input is never uploaded.
Query String Converter
Convert URL query parameters to readable JSON and turn flat JSON objects back into an encoded query string.
The result uses syntax highlighting for JSON keys and values or query parameter names and values. Multiline JSON output can be collapsed to a compact summary and expanded again from the output toolbar.
Repeated parameters are preserved as arrays when converting to JSON. JSON arrays become repeated query parameters, and values are encoded with the browser's standard URL rules.
Only flat JSON values are supported for reverse conversion. Nested objects and null values are rejected so the output remains predictable.
All processing happens locally in your browser. No query data is uploaded.