100% local — your data never leaves your browser

JSON to Query String Converter — Free Online Tool

Convert a flat JSON object into a URL query string in your browser. Free, private and offline-friendly: your data never leaves your device.

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JSON input

Query String output

Why convert JSON to a query string?

When you need to build a URL from structured data, turning a JSON object into a properly encoded query string by hand is fiddly. Paste a flat JSON object above and get a ready-to-use query string in an instant.

How it works

The converter encodes each key and value of your flat JSON object into a URL query string. An array of scalar values is expanded into repeated keys, while a nested object stops it with a clear error since it cannot be represented unambiguously, and a null becomes an empty value. As the inverse of the Query String to JSON tool, it completes the round trip, and because it runs locally your data never leaves your device.

Frequently asked questions

Does my JSON get sent to a server?
No. The query string is built entirely in your browser, so your JSON and its values never leave your device.
Can it handle nested objects or arrays?
Flat objects only. An array of scalar values becomes repeated keys (a=1&a=2), mirroring the Query String to JSON tool; nested objects are rejected with a clear error.
What happens to null values?
A null value is encoded as an empty value, producing a key with no value in the resulting query string.

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