Query String Parser
Break a query string down into key-value pairs and view it as JSON.
Query String Builder
Build a URL-encoded query string from key-value pairs.
Input data is processed in your browser
Data is never sent to a server
Tool
What is Query String Builder?
Query String Builder lets you generate a URL-encoded query string just by entering key-value pairs. Values containing special characters or non-ASCII text are automatically converted to a safe format, preventing manual encoding mistakes. Useful for constructing API request URLs and building test URLs.
How to Use
- Optionally enter a base URL (leave blank to generate just a "?"-prefixed query string).
- Click "Add Parameter" to add key-value pairs.
- With auto-generate enabled, the query string updates instantly as you type.
- Click "Copy Result" to copy to clipboard.
FAQ
Are values automatically URL-encoded?
Yes. Values containing spaces, special characters, or non-ASCII text are automatically encoded into a safe format.
Can I add the same key multiple times?
Yes. Adding multiple parameters with the same key produces an array-style query string (key=a&key=b).
What if the base URL already has a query string?
New parameters are appended with "&" if a query string already exists, or "?" if it doesn't.
Is my data sent to a server?
No. All processing happens in your browser using the built-in URLSearchParams API.
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