Query String Builder
Turn key value rows into a properly encoded query string or full URL.
Build correct query strings, every time
Query strings look simple but break easily — an unencoded space, ampersand, or special character can split a parameter or corrupt a value. This builder turns your key-value rows into a properly encoded query string or a complete URL, handling the escaping so the result works the first time.
It is handy for constructing API test URLs, building tracking links, assembling deep links, and generating parameterized URLs without hand-encoding each value. What you get is a valid string you can paste straight into a browser, a request, or your code.
Private and instant
The URL is assembled locally in your browser using the native URL API, so your parameters and values never leave your device. Copy the encoded result when it looks right.
Frequently Asked Questions
What does this builder create?
It builds a URL query string from key value rows and safely percent-encodes each value.
Can it append to a base URL?
Yes. Enter a base URL and the tool outputs the full URL with the generated query string.
Does it support duplicate keys?
Yes. Repeated keys are kept as repeated query parameters.
Is anything uploaded?
No. Query strings are built locally.
Need campaign links? Use the UTM builder too.