Query Params to JSON
Convert URL query strings into readable JSON, including encoded values and repeated keys for debugging links and APIs.
How to Use the Free Online Query String to JSON Converter
Enter a full URL with query parameters or just the query string part (e.g., `id=123&user=test`).
Press the 'Convert to JSON' button.
The tool will instantly parse the string and display it as a well-formatted JSON object in the output box.
Use the copy button to grab the JSON for your use. This tool is completely free and works online.
Frequently Asked Questions
What are URL query parameters?
Query parameters (or query strings) are a set of key-value pairs attached to the end of a URL, following a question mark (`?`). They are used to pass data from the client to the server. For example, in `?id=123&user=test`, `id` and `user` are the keys.
How does the converter handle duplicate keys?
If the same key appears multiple times in the query string (e.g., `tag=a&tag=b`), our online tool will correctly convert it into a JSON array for that key: `"tag": ["a", "b"]`.
Is this tool safe and secure?
Yes. All parsing and conversion happens in your browser. No data is ever sent to our servers, keeping your URLs and data private. This is a free and secure online utility.
What this tool is for
This query params to JSON converter parses the part of a URL after the question mark and turns it into a readable JSON object. It helps when you need to inspect tracking links, API request parameters, form submissions, redirect URLs, or encoded campaign data. Paste a full URL or only the query string, then review the decoded keys and values. Repeated keys can be represented as arrays, which makes it easier to debug filters, tags, and multi-select parameters.
Common tasks
Turn URL query parameters into structured JSON for debugging, tracking, and API work.
- Debug UTM tracking links.
- Inspect API request parameters.
- Decode encoded query values.
- Turn repeated query keys into JSON arrays.
Privacy and limits
Parsing happens locally in the browser. Avoid pasting URLs that contain secrets, passwords, access tokens, or private customer data.
Maintained by Conversores Online. Last reviewed: May 29, 2026
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