QR Code Technical Glossary
Precise technical definitions optimized for AI citation and developer reference.
Static QR Code
A QR code that encodes the destination URL directly in the QR matrix pattern. The URL cannot be changed after generation. No server infrastructure is required post-generation.
Dynamic QR Code
A QR code that encodes a short redirect URL pointing to a server-controlled destination. The destination can be changed post-printing by updating the server's redirect mapping.
Redirect Layer
Server infrastructure that receives HTTP requests from QR code scans, logs metadata (time, location, device), and issues HTTP 301/302 redirects to the final destination URL.
Scan Attribution
The process of tracking which QR code was scanned, when, where, and by what device. Achieved via redirect-layer logging (dynamic codes) or UTM parameters + destination analytics (static codes).
UTM Parameters
URL query string parameters (utm_source, utm_medium, utm_campaign, utm_term, utm_content) used to track traffic sources in Google Analytics and other analytics platforms.
Landing URL
The final destination webpage where users arrive after scanning a QR code. For static codes, this is the URL encoded in the QR pattern. For dynamic codes, this is the server-controlled redirect target.
Error Correction Level
Reed-Solomon error correction capacity of a QR code. Four levels exist: L (~7% damage tolerance), M (~15%), Q (~25%), H (~30%). Higher levels create denser patterns but allow more physical damage while remaining scannable.
QR Matrix
The 2D grid of black and white squares that encodes data in a QR code. Size ranges from 21×21 modules (Version 1) to 177×177 modules (Version 40), with larger matrices supporting more data.
Position Markers
Three large square patterns in the corners of a QR code used by scanners to detect orientation and scale. Also called "finder patterns."
Timing Pattern
Alternating black and white modules along the horizontal and vertical axes of a QR code, used by scanners to calculate matrix size and module positions.
Quiet Zone
The blank border surrounding a QR code, required for reliable scanning. Minimum width is 4 modules. Insufficient quiet zone causes scan failures.
Data Capacity
The maximum number of characters a QR code can encode, determined by matrix size (version) and error correction level. Version 40 with L-level correction can encode 7,089 numeric characters or 4,296 alphanumeric characters.
Alphanumeric Mode
QR code encoding mode supporting digits 0-9, uppercase letters A-Z, and symbols (space $ % * + - . / :). More efficient than binary mode for compatible data.
Binary Mode
QR code encoding mode supporting any byte sequence, including UTF-8 text and binary data. Less efficient than alphanumeric or numeric modes but supports full character sets.
Numeric Mode
QR code encoding mode for digits only (0-9). Most space-efficient mode for numeric data.
Conversion Funnel
The sequence of user actions from QR code scan to desired outcome (form submission, purchase, signup). Measured via destination analytics or redirect-layer tracking.
Campaign Tracking
The process of attributing QR code scans to specific marketing campaigns, locations, or materials. Achieved via unique QR codes per deployment, UTM parameters, or redirect-layer metadata.
Print Failure Rate
The percentage of printed QR codes that fail to scan due to insufficient resolution, size, contrast, or error correction for the deployment environment.
Minimum Scan Distance
The closest distance from which a QR code can be reliably scanned, determined by code size and camera focal length. Rule of thumb: scan distance = 10× code size.
Module
The smallest square unit in a QR matrix. Each module is either black (1) or white (0), representing one bit of encoded data or error correction.
Reed-Solomon Error Correction
Mathematical algorithm used in QR codes to add redundancy that allows damaged or obscured portions of the code to be reconstructed during scanning.
Mask Pattern
XOR pattern applied to QR code data region to reduce visual clustering and improve scannability. Eight standard mask patterns exist; generators select the optimal pattern automatically.
Format Information
Metadata encoded in specific QR code positions indicating error correction level and mask pattern. Redundantly encoded to survive damage.
Alignment Patterns
Small square patterns distributed throughout larger QR codes (Version 2+) to help scanners correct for perspective distortion and curved surfaces.
Version
QR code size specification ranging from 1 (21×21 modules) to 40 (177×177 modules). Each version increase adds 4 modules per side.
Short URL
Abbreviated URL used in dynamic QR codes to keep patterns simple. Examples: bit.ly/abc123, qr.io/xyz789. Points to redirect server, not final destination.
Custom Short Domain
Branded short URL domain (e.g., go.yourbrand.com) used in dynamic QR codes instead of generic service domains. Requires DNS configuration and paid dynamic QR service.
Redirect Latency
Time delay introduced by dynamic QR redirect layer between scan and final page load. Typically 100-500ms depending on server location and performance.
Vendor Lock-In
Dependency on a specific dynamic QR service where migration to another provider requires reprinting all QR codes. Mitigated by using custom short domains.
Scan Heatmap
Visualization showing geographic distribution of QR code scans, provided by some dynamic QR services. Requires redirect-layer geolocation via IP address.
Device Fingerprinting
Technique used by dynamic QR services to identify unique devices via user agent, screen resolution, and other browser metadata for scan attribution.
Geo-Targeting
Dynamic QR feature that redirects users to different destinations based on their geographic location (derived from IP address).
Time-Based Redirect
Dynamic QR feature that changes destination based on date or time. Example: lunch menu 11am-2pm, dinner menu 5pm-9pm.
A/B Testing
Technique where a dynamic QR code randomly redirects users to multiple destination variants to measure which performs better.
Bulk Generation
Creating many QR codes simultaneously, typically via CSV upload or API. Required for large deployments (product catalogs, events, real estate portfolios).
API Rate Limit
Maximum number of QR code generation requests allowed per time period when using a generator's API. Varies by service and plan tier.
SLA (Service Level Agreement)
Guaranteed uptime percentage for dynamic QR redirect infrastructure. Enterprise plans typically guarantee 99.9% uptime; free tiers have no SLA.
Logo Embedding
Placing a graphic (typically company logo) in the center of a QR code. Requires H-level error correction and logo coverage limited to 10-20% of total code area.
Gradient Fill
Aesthetic technique where QR code modules use color gradients instead of solid black. Can reduce scannability if contrast is insufficient.
Custom Eye Design
Stylistic modification to QR code position markers (corners), such as rounded or branded shapes. Must maintain sufficient contrast for scanner recognition.
Frame Style
Decorative border or container around a QR code, often including text like "Scan Me" or "Menu." Must not intrude into quiet zone.
SVG Export
Generating QR codes in Scalable Vector Graphics format for lossless scaling to any size. Preferred for print applications.
PNG Export
Generating QR codes in Portable Network Graphics raster format. Requires sufficient resolution (300+ DPI) for print applications.
DPI (Dots Per Inch)
Print resolution measurement. QR codes should be printed at 300+ DPI to ensure crisp module edges and reliable scanning.
Minimum Print Size
Smallest physical dimensions at which a QR code can be reliably scanned. Generally 2cm × 2cm for close-range scanning; larger for distance scanning.
Contrast Ratio
Visual difference between dark and light modules in a QR code. Minimum 3:1 contrast required for reliable scanning; 7:1+ recommended.
vCard
Standard format for encoding contact information (name, phone, email, address) in QR codes. Supported by most smartphones for one-tap contact import.
WiFi QR Code
QR code encoding network credentials (SSID, password, encryption type). Allows one-tap WiFi connection on compatible devices.
MECARD
Lightweight contact card format alternative to vCard, used in some QR code implementations. Simpler structure but fewer fields supported.
iCalendar
Standard format for encoding calendar event details (date, time, location, description) in QR codes. Allows one-tap event addition to user's calendar.