Is my query string uploaded to a server?

No. Parsing happens entirely in your browser, so the query string and any values it contains stay on your device.

How are repeated keys handled?

Repeated keys such as a=1&a=2 are collected into a JSON array, so no values are lost when the same parameter appears more than once.

Do I need to strip the leading question mark?

No. A leading ? or # is ignored automatically, so you can paste a full query fragment without cleaning it up first.

Query String to JSON Converter

Query String to JSON Converter — Free Online Tool

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

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Indentation

Swap: JSON → Query String

Query String input

JSON output

Why convert a query string to JSON?

URL query strings are convenient to pass around but awkward to read or process in code. Paste a query string above and get a clean JSON object you can inspect, log, or feed into your application.

How it works

The converter parses your input with the browser’s URLSearchParams, so the behavior matches exactly how the platform reads URLs. A leading ? or # is ignored, and repeated keys are grouped into a JSON array so duplicate parameters survive the conversion. Everything runs locally, which means your data never leaves your device.

Frequently asked questions

Is my query string uploaded to a server?: No. Parsing happens entirely in your browser, so the query string and any values it contains stay on your device.
How are repeated keys handled?: Repeated keys such as a=1&a=2 are collected into a JSON array, so no values are lost when the same parameter appears more than once.
Do I need to strip the leading question mark?: No. A leading ? or # is ignored automatically, so you can paste a full query fragment without cleaning it up first.