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URL Query String to JSON Converter — Both Directions

Convert between a URL query string (?key=value&key2=value2) and JSON in either direction — correctly handling repeated keys as arrays and URL-encoding special characters — useful for debugging an API request or building one from structured data.

How to use Query <> JSON

1. Paste your query string or JSON.
2. Pick the conversion direction.
3. Copy the result.

Frequently asked questions

How are repeated query parameters handled?

Keys that appear multiple times (like tag=a&tag=b) convert to a JSON array rather than only keeping the last value, which is the common bug in a naive implementation.

Does it handle URL encoding correctly?

Yes — special characters and spaces are properly encoded when converting to a query string, and decoded when converting from one.

Does it handle nested JSON objects?

Nested objects convert using bracket notation (key[subkey]=value), a common convention for representing structure in a flat query string.

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Also searched for: query string to json converter · json to url params online · parse url query string tool

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