URL Query String Builder

Build a URL with query parameters from key/value pairs, using form encoding (space as +) or RFC 3986 (%20). Import parameters from an existing URL.

Base URL

Parameters

Encoding

Resulting URL

https://example.com/search?q=coffee+%26+tea&page=2

Import parameters from an existing URL

What is URL Query Builder?

The query builder turns a base URL and a list of key/value pairs into a correctly encoded URL. Choose HTML form encoding (spaces as +, like URLSearchParams) or strict RFC 3986 percent-encoding (spaces as %20), and import the parameters of an existing URL to edit them.

How to use URL Query Builder

Enter the base URL, e.g. https://example.com/search.
Fill in the key and value rows; use Add parameter for more and × to remove one.
Choose the encoding.
Copy the resulting URL. To edit an existing link, open "Import parameters from an existing URL".

Example

Input

https://example.com/search, q = coffee & tea, page = 2

Output

https://example.com/search?q=coffee+%26+tea&page=2

With RFC 3986 encoding: https://example.com/search?q=coffee%20%26%20tea&page=2

When to use URL Query Builder

Use it to construct API calls, tracking links or test URLs without hand-encoding special characters like &, = or spaces. If you only want to read an existing URL's parameters, the URL Parser is quicker.

How URL Query Builder works

Rows with an empty key are skipped and values are encoded exactly once. Form encoding uses URLSearchParams.toString(); RFC 3986 mode uses encodeURIComponent and additionally escapes ! ' ( ) *. Any query string already in the base URL is replaced and its #fragment is kept at the end. Import splits a URL at ? and # and decodes the pairs with URLSearchParams.

Common Use Cases

Build a search URL whose value contains & or =.
Create UTM-tagged campaign links.
Prepare encoded GET requests for API testing.
Edit one parameter of a long URL without breaking the rest.

FAQs

Should spaces be + or %20?

Both are understood in query strings by most servers. + comes from HTML form encoding; %20 is the generic URI encoding and is safer when the receiver is not a typical web framework.