Build a URL with query parameters from a form.
Assembling a query string by hand is fiddly: you have to remember the question mark before the first parameter, ampersands between the rest, equals signs in the right places, and percent encoding for any value with spaces or special characters. One missed ampersand and the link silently passes the wrong data. This query string builder turns that into a simple form: enter a base URL, add name and value pairs, and the assembled URL appears below.
Encoding is handled for you. Values are escaped with the browser standard URLSearchParams logic, so a value like summer sale 2026 or an email address with a plus sign comes out correctly encoded without you thinking about it. If the base URL already has parameters, the new ones are appended after the existing ones rather than overwriting them, and you can add or remove rows freely as the preview updates live. It is a quick way to construct API request URLs, test links with specific filter or pagination parameters, or compose campaign URLs before shortening them with a tool like ReSlug.
The builder runs entirely in your browser, so the URLs you compose stay on your machine. When the result looks right, one click copies it to your clipboard.
Put the destination in the Base URL field, including https://. Existing query parameters on the base URL are kept.
Fill in the name and value fields for each parameter. Click Add parameter for more rows, or use the trash button to remove one.
The Assembled URL box updates live with every change, with all values percent-encoded automatically.
Click Copy URL to put the finished link on your clipboard, ready to paste into a browser, an API client, or a campaign.
A query string parameter is a name and value pair appended to a URL after a question mark, such as ?q=shoes. Multiple parameters are joined with ampersands, and web servers and scripts read them to control search terms, filters, pagination, and tracking.
No. The builder percent-encodes values automatically, so spaces, ampersands, equals signs, and non-ASCII characters in a value will not break the URL.
They are preserved. The parameters you add in the form are appended after the existing ones, so nothing in the original URL is lost or overwritten.
Yes. Repeating a name like tag=a&tag=b is valid in a URL, and the builder appends each row independently, so duplicates are kept. How they are interpreted is up to the receiving server.
No formal limit is defined in the URL standard, but browsers, servers, and CDNs impose practical limits, commonly around 2000 characters for safe compatibility. Very long URLs are better replaced with a short link or a POST request.
ReSlug builds tracked, branded short links from any URL with one form.