URL Query String Builder
Build a URL query string from key-value pairs, correctly encoded.
Assembling parameters correctly
A URL query string — the part after the question mark — is a set of key-value pairs, and building one correctly means encoding each value and joining them with the right separators. This assembles a valid, properly-encoded query string from the pairs you enter, so you get a working URL rather than one broken by an unencoded character.
Enter your key-value pairs and the query string is built.
Where hand-building goes wrong
The mistakes people make by hand are always the same: forgetting to encode a value that contains a space, an ampersand or an equals sign, which breaks the URL's structure, or mishandling a parameter that appears more than once. Building it properly encodes every value and formats the whole thing correctly. It pairs naturally with a parser for the reverse job — taking a query string apart — and between them you can construct and inspect URL parameters without the encoding headaches.
Questions & answers
Why not just type the query string myself?
Because unencoded special characters — spaces, ampersands, equals signs — in a value break the URL. Building it encodes each value correctly.
Can it handle repeated parameters?
Yes — parameters that appear more than once are formatted correctly rather than clobbering each other.
Is anything uploaded?
No. The string is built in your browser.