URL

A URL (Uniform Resource Locator) uniquely identifies the location of a page or file on the Web. It consists of a scheme (https://), domain (example.com), path (/page), and optional query parameters (?key=value). URLs are by far the most common data stored in QR codes - scanning one automatically opens the browser to that page.

In practice, URL length directly determines QR code size. Each character consumes 1 byte in Binary Mode, so a long URL with UTM tracking parameters (200+ characters) requires Version 7 or larger. Converting URLs to uppercase triggers Alphanumeric Mode, reducing data size by roughly 40%. This is safe because HTTP schemes and domain names are case-insensitive.

URL shorteners can further reduce size, but introduce trade-offs: redirect latency and the risk of broken links if the service shuts down. Using your own domain for short URLs (e.g., qraft.cc/abc) balances branding with risk mitigation. For printed QR codes with long lifespans, design short self-hosted URLs rather than depending on third-party shorteners.