Reference
Plain-language definitions for the terms that come up across our guides and tools — no jargon left unexplained.
Short for "Quick Response" code — a two-dimensional barcode made of a grid of black and white squares that a camera can read instantly. Unlike a traditional 1D barcode, a QR code can hold URLs, text, contact details, WiFi credentials, and more, not just a single numeric ID.
A QR code with its destination permanently encoded into the pattern itself. It never expires and requires no server to function. See our full guide: static vs. dynamic QR codes.
A QR code that encodes a short redirect link rather than the real destination. A third-party server resolves that link on every scan, which lets the destination be changed after printing but makes the code dependent on that server staying online. More in our static vs. dynamic guide.
One single black or white square within a QR code's grid — the smallest unit of the pattern. A code's total module count depends on its version and how much data it's encoding; more data means more modules and a denser-looking code.
The blank margin that must surround a QR code on all sides. It isn't decorative — scanners use it to detect where the pattern starts and stops. Cropping it too tight against text or design elements is a common cause of failed scans, covered in our restaurant menu setup guide.
A built-in redundancy in every QR code that lets it still scan correctly even if part of the pattern is damaged, dirty, or covered — for example, by a logo placed in the center. Higher error-correction levels tolerate more damage but produce a denser code.
QR codes come in versions 1 through 40, each specifying a fixed grid size (version 1 is 21×21 modules, version 40 is 177×177). A generator automatically picks the smallest version that fits your data — longer input means a higher version and a denser-looking code.
The scheme used to pack your data into the code: numeric (digits only), alphanumeric (a limited character set), byte (any text or binary data), or kanji. Byte mode is the most flexible and what's used for URLs and general text, but it's also the least space-efficient per character.
How distinct a code's foreground color is from its background. Low-contrast color pairs (light gray on white, pale colors on pale backgrounds) scan unreliably, especially once printed. Dark-on-light is the safest default.
A static QR code that encodes a network name and password in a standardized format, letting a phone's camera join the network directly without anyone typing the password. Build one with the WiFi QR code generator.
The behavior of a WiFi QR code: scanning it prompts the phone to join the encoded network automatically, instead of the user manually selecting a network and typing a password.
A logo, label, or branding mark that some QR generators stamp onto the downloaded image — often to promote their own service. Every code generated on this site downloads with no watermark added, regardless of which tool you use.
Generating many QR codes from a list of inputs in one pass, rather than one at a time — useful for things like one code per table, per product, or per location. See the bulk generator.
A short URL (such as one from a link shortener) that forwards to another destination. This is what a dynamic QR code actually encodes — the code points to the redirect link, and the link's owner controls where it currently forwards to.