Glossary Web & HTTP

Query string

A query string is the part of a URL after the question mark that carries named values for the server, such as ?q=shoes&page=2.

Last reviewed: 2026-10-03

In more detail

Pairs are written name=value and joined by &. Reserved characters in names and values must be percent-encoded (a space becomes %20 or +). Query strings are visible in the address bar, logs and the browser history, so never put passwords or tokens in them. Marketing links add tracking parameters such as utm_source this way.

Try these tools

Query String Builder

Build a properly URL-encoded query string from key/value pairs using a simple form.

URL Parser

Paste any URL and instantly see its protocol, host, port, path, query parameters, and hash broken down into readable parts.

UTM Link Builder

Build a UTM-tagged tracking URL with source, medium, campaign, term, and content parameters for Google Analytics campaign tracking.

In more detail

Try these tools

Query String Builder

URL Parser

UTM Link Builder

See also