Query String to JSON Converter
Convert URL query strings to JSON and JSON back to a query string.
Three steps, no reading required.
Paste your input
Drop text, code, or data into the input pane — from an API response, a file, anywhere.
Pick a mode
Toggle the modes above the output. The result updates instantly as you type.
Copy the result
Grab the output with Copy or Download, or fix the error shown if the input is invalid.
Try it with a sample.
name=Ada&role=admin&role=dev&filter[status]=open&tags[]=a&tags[]=b
Upload & hope
- Sends your input to a server to process it
- Asks for an account after a few free uses
- Limits input size on the free tier
Runs where you are
- Processes everything inside your browser tab
- No account, ever
- No artificial size limit
Questions worth answering upfront.
No. Conversion runs entirely in your browser. Your query strings are never uploaded, stored, or logged.
Repeated keys (role=a&role=b) and keys with a [] suffix collapse into a JSON array, so nothing is lost.
Yes. Bracket notation like filter[status] or a[b][c] parses into nested JSON objects, and JSON objects serialize back using the same notation.
Yes. Percent-encoding and + are decoded on the way in, and values are percent-encoded on the way out. Values stay strings so conversion round-trips.
Yes. Every tool on DevUtilsNow is free to use with no account required.
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Guides that pair with this tool
How to Convert a Query String to JSON (and Back)
Parse a URL query string into JSON and serialize JSON back — how repeated keys, bracket notation, and encoding are handled.
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