JSON to Query String
Serialize JSON objects into URL-encoded query strings for APIs and links.
- 100% client-side · your data never leaves your browser
- Instant, no rate limits
- Free, no sign-up
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Paste JSON into the panel on the left — everything runs privately in your browser.
Overview
JSON to Query String — Build URL Params Online
Convert a JSON object into a URL query string. Turn {"page":2,"sort":"name"} into page=2&sort=name, ready to append to an endpoint. It is the quick way to build request URLs from structured parameters, share a pre-filled link, or reproduce an API call from a JSON config. Values are URL-encoded so special characters travel safely. Runs entirely in your browser.
How the conversion works
Each top-level key becomes a query parameter and its value is percent-encoded so spaces, ampersands, and Unicode survive transmission. Nested objects and arrays are serialized into bracketed or repeated-key notation so structured parameters still fit the flat key=value model that URLs require.
The result is a ready-to-use query string you can append after a ? in your endpoint, paste into a browser, or feed to an HTTP client.
When it is useful
- Building API request URLs from a JSON parameter object
- Creating shareable links that pre-fill filters, search, or pagination
- Reproducing a documented API call from its JSON example
- Generating tracking or UTM URLs from structured campaign data
Round-tripping with Query String to JSON
This tool's inverse, Query String to JSON, parses a URL's parameters back into a JSON object — useful when you capture a request and want to inspect or edit its parameters as structured data. Together the two tools let you move freely between URL parameters and JSON.
FAQ
Frequently asked questions
How are nested objects handled?
Nested objects and arrays are serialized using bracket or repeated-key notation so they fit the flat structure of a query string. Deeply nested shapes are best flattened first for predictable output.
Are values URL-encoded?
Yes. Every value is percent-encoded so spaces, ampersands, equals signs, and non-ASCII characters do not break the URL.
Does it add the leading question mark?
The output is the query string itself (key=value&key=value). Add a ? when you append it to your endpoint path.
Can I convert a query string back to JSON?
Yes. Use the Query String to JSON tool to parse URL parameters back into a structured JSON object.
Continue with a related tool
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