Query string builder & parser

How it works

Each parameter row's key and value are URL-encoded with encodeURIComponent() and joined with &, then appended to the base URL — after a ? if the base doesn't already contain one, or after an & if it does, so you can add params on top of an existing query string without breaking it.

FAQ

Does it parse an existing URL I paste in back into separate key/value rows?

Not currently — the base URL field is treated as a literal string that params get appended to, rather than being split apart into its own editable rows first.

Why do special characters in my values look different in the result URL?

encodeURIComponent() percent-encodes anything that isn't a valid URL character — a space becomes %20, an & becomes %26 — so the query string stays valid even when a key or value contains reserved characters.