Query Builder

Build a URL query string from key-value pairs with correct percent-encoding — handy for UTM campaign links and API URLs, with the full URL and query string ready to copy.

Keys and values are percent-encoded (spaces become %20). Any query already on the base URL is replaced by the parameters above; a #fragment is kept.

Full URL · 3 params 
https://example.com/page?utm_source=newsletter&utm_medium=email&q=hello%20world
Query string 
utm_source=newsletter&utm_medium=email&q=hello%20world