Query String ↔ JSON
Convert a URL query string to JSON and back. Repeated keys become arrays, all done locally in your browser.
Paste a URL's query string to see it as structured JSON, or paste JSON to generate a properly encoded query string, handy for debugging API requests, reverse-engineering an endpoint's parameters, or building a URL by hand without fumbling ampersands and percent-encoding.
How to use it
- Paste a query string (with or without the leading ?) or a JSON object into either side
- Watch it convert instantly in the other panel as you type
- Copy the JSON or the encoded query string to use in your code or URL
Frequently asked questions
- Does it handle nested objects and arrays?
- Yes. Bracket notation like user[name]=Alex&tags[]=a&tags[]=b converts to nested JSON objects and arrays, and converts back the same way.
- What happens to duplicate keys like ?color=red&color=blue?
- Repeated keys are collected into a JSON array automatically, so color=red&color=blue becomes {"color": ["red", "blue"]}.
- Are values automatically converted to numbers or booleans?
- You can toggle type coercion on or off, with it on, page=2 becomes a number and active=true becomes a boolean; with it off, everything stays a string, which matches how query strings actually work on the wire.
- Does it URL-encode special characters for me?
- Yes, converting JSON to a query string automatically percent-encodes spaces, symbols, and unicode, and the reverse direction decodes them back.
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Nothing is uploaded
The file never leaves your device. There is no server to send it to, so there is nothing to leak, log, or subpoena.
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No signup, no limits
No account, no email, no daily cap, no watermark, and no paid tier waiting behind the third file.
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Works offline
Load the page once and it keeps working with the network off, because all the work was always happening locally.