Query String Builder
Build and parse URL query parameters
Result
Your URL will appear here...Common Parameters
URL Encoding
• Space → %20 or +
• & → %26
• = → %3D
• ? → %3F
• Special chars are automatically encoded
About the Query String Builder
This query string builder lets you add, edit and remove parameters in a table and produces a correctly encoded query string — so values containing spaces or ampersands cannot break the URL structure.
A query string builder handles the encoding that hand-writing gets wrong. Every parameter value has to be percent-encoded, and the character that breaks things most often is the ampersand: a value containing one is read as the start of another parameter, so half the value silently disappears.
Building parameters in a table also makes the structure visible. Adding a UTM campaign set, removing a stale parameter, or correcting one value in a long URL is far easier as rows than as one string full of ampersands.
The common use is campaign URLs. UTM parameters are fiddly to assemble by hand and easy to get subtly wrong — a mistyped parameter name means the campaign simply does not attribute, which is not noticed until the report is empty.
How to use the Query String Builder
- Enter the base URL. Provide the address the parameters attach to.
- Add your parameters. Enter each name and value as a row.
- Check the encoding. Confirm values containing spaces or ampersands were escaped.
- Copy the URL. Take the assembled, correctly encoded address.
Query String Builder features
- Add, edit and remove parameters as table rows
- Automatic percent-encoding of values
- Handles ampersands and spaces inside values
- Parse an existing query string back into rows
- Suitable for UTM campaign URLs
- Runs entirely in your browser
Frequently asked questions
Why does an ampersand in a value break a URL?
Unencoded, it reads as the start of another parameter, so the rest of your value is silently lost.
Are values encoded automatically?
Yes. Every value is percent-encoded so spaces, ampersands and other reserved characters are safe.
Can I edit an existing query string?
Yes. Paste the URL and its parameters are parsed back into editable rows.
Is this useful for UTM links?
Yes. UTM parameters are fiddly by hand, and a mistyped name means the campaign silently fails to attribute.
Is anything uploaded?
No. The builder runs entirely in your browser.