Glossary
QR code terms, defined
Static or dynamic, error correction, quiet zone, payload. The vocabulary of QR codes in plain English, one clear definition at a time.
Campaign URL
A campaign URL is a destination link built for a specific marketing push, usually tagged with UTM parameters so its traffic can be measured.
Data capacity
Data capacity is the maximum amount of information a QR code can hold, set by its version, error-correction level, and the type of data encoded.
Data masking
Data masking is a step in QR encoding that XORs the pattern with one of several mask templates to avoid large blank or solid areas that confuse scanners.
Deep link
A deep link is a URL that opens a specific screen inside a mobile app rather than the app's home screen or a website.
DPI (print resolution)
DPI (dots per inch) is how many printed dots fit in an inch. Higher DPI means finer detail, and 300 DPI is the usual minimum for crisp printed QR codes.
Dynamic QR code
A dynamic QR code encodes a short redirect URL instead of the final destination, so you can change where it points after it's printed.
Error correction level
Error correction level is how much redundant data a QR code carries so it still scans when damaged, graded L, M, Q, or H from least to most.
Finder pattern
Finder patterns are the three large nested squares in a QR code's corners that let a scanner locate and orient the code.
HTTP redirect (301 vs 302)
An HTTP redirect is a server response that sends a browser on to a different URL; a 301 is permanent, a 302 is temporary.
Landing page
A landing page is the web page a visitor reaches after clicking a link or scanning a code, the first thing they see, built to match the source's promise.
Module
A module is a single square in a QR code, the smallest unit of the black-and-white grid that a scanner reads as one bit.
Payload
The payload is the actual data encoded in a QR code, most often a URL, but also text, contact details, or Wi-Fi credentials.
QR code vs barcode
A barcode is a one-dimensional pattern of lines read left to right; a QR code is a two-dimensional grid that holds far more data and scans from any angle.
QR version
A QR code's version is its size in modules, numbered 1 to 40. Version 1 is 21×21 modules, and each step up adds 4 modules per side.
Quiet zone
The quiet zone is the empty margin around a QR code, usually four modules wide, that lets a scanner tell where the code begins and ends.
Redirect loop
A redirect loop is an error where a URL redirects to another URL that eventually points back to the first, so the browser never reaches a real page.
Scan event
A scan event is a single recorded scan of a dynamic QR code, capturing data like the timestamp, approximate region, and device type.
Short link
A short link is a brief URL that redirects to a longer destination, making it easier to print, share, and repoint.
Static QR code
A static QR code has the destination URL encoded directly into its pattern, so the link can never change once the code is printed.
SVG vs PNG (for print)
SVG is a vector format that stays crisp at any size, making it the right choice for printing QR codes large; PNG is a fixed-resolution image best for screens and small print.
UTM parameters
UTM parameters are tags added to the end of a URL (like utm_source and utm_campaign) that let analytics tools attribute a visit to a specific campaign.
Vanity URL
A vanity URL is a short, human-readable custom link, like example.com/spring, chosen to be memorable and on-brand.
vCard QR code
A vCard QR code encodes contact details in the vCard format, so scanning it prompts the phone to save a new contact in one tap.
Wi-Fi QR code
A Wi-Fi QR code encodes a network's name, password, and security type, so scanning it joins the network without typing the password.
Reference tables
Error-correction levels, version capacity, print sizes, redirect codes. The numbers behind the terms.
QR code answers
Why won't my code scan? Can I change it after printing? Direct fixes to the common problems.