1 What Is a QR Code?

A QR code (Quick Response code) is a two-dimensional barcode that stores information in a pattern of black and white squares. Invented in 1994 by Masahiro Hara at Denso Wave (a Toyota subsidiary), QR codes were originally designed to track automotive parts during manufacturing.

Unlike traditional barcodes that store data horizontally, QR codes store data both horizontally and vertically. This allows them to hold significantly more information—up to 7,089 numeric characters or 4,296 alphanumeric characters.

QR Code vs Barcode: Key Differences

2 How QR Codes Work

Every QR code contains several key components that work together to store and transmit data:

Anatomy of a QR Code

• Finder Patterns: The three large squares in the corners help scanners locate and orient the code, regardless of the scanning angle.
• Alignment Pattern: The smaller square (in larger QR codes) helps correct distortion when scanning at angles.
• Timing Patterns: Alternating black and white modules between finder patterns establish the coordinate system.
• Quiet Zone: The white border around the code (minimum 4 modules wide) helps scanners identify where the code begins and ends.
• Data Modules: The actual pattern that encodes your information.
• Format Information: Stores the error correction level and masking pattern.
• Version Information: Indicates the QR code version (size/capacity).

Error Correction Levels

QR codes include Reed-Solomon error correction, allowing them to remain scannable even when partially damaged. There are four levels:

3 Types of QR Codes

QR codes can encode various types of data. Here are the most common content types:

URL/Website Links

The most common use case. When scanned, the device opens the specified website in a browser. Example: https://example.com

Plain Text

Displays text content directly on the device. Useful for short messages, instructions, or information that doesn't require internet access.

WiFi Network Credentials

Allows instant connection to a WiFi network without typing passwords. Format: WIFI:T:WPA;S:NetworkName;P:Password;;

Contact Information (vCard)

Stores contact details that can be saved directly to the phone's address book. Includes name, phone, email, address, and more.

Email

Opens the email client with a pre-filled recipient, subject, and body. Format: mailto:[email protected]?subject=Hello&body=Message

SMS/Text Message

Opens the messaging app with a pre-filled recipient and message. Format: sms:+1234567890?body=Hello

Phone Number

Initiates a phone call to the specified number. Format: tel:+1234567890

Geographic Location

Opens maps application with specified coordinates. Format: geo:51.5074,-0.1278

Calendar Event

Creates a calendar event with date, time, location, and description.

App Store Links

Direct links to download apps from the App Store or Google Play.

4 Static vs Dynamic QR Codes

Understanding the difference between static and dynamic QR codes is crucial for choosing the right type for your project.

Static QR Codes

Static QR codes encode data directly into the code pattern. The data is permanent and cannot be changed after creation.

Dynamic QR Codes

Dynamic QR codes encode a short redirect URL that points to your destination. The redirect can be changed at any time without altering the physical code.

When to Use Each Type

Use Static QR codes for:

• WiFi passwords (works offline)
• Business cards with contact info
• Product serial numbers
• Permanent, unchanging information
• Situations where privacy is paramount

Use Dynamic QR codes for:

• Marketing campaigns (track ROI)
• Print materials (fix typos without reprinting)
• Menus (update seasonally)
• Event promotions (update dates/venues)
• Any scenario where content may change

5 Creating QR Codes

Creating a QR code is straightforward with modern tools. Here's a step-by-step process:

Step 1: Determine Your Content Type

Decide what action you want the QR code to trigger: open a URL, connect to WiFi, save a contact, etc.

Step 2: Choose Static or Dynamic

Consider whether you'll need to edit the destination or track scans. Marketing campaigns typically benefit from dynamic codes.

Step 3: Enter Your Content

Input your URL, text, WiFi credentials, or other data. For URLs, use the shortest possible link to keep the QR code simple.

Step 4: Customise the Design

Adjust colours, add a logo, and choose a style that matches your brand (more on this in the Design section).

Step 5: Test Before Deploying

Always test your QR code with multiple devices and scanning apps before printing or publishing.

Step 6: Download in the Right Format

• PNG: Best for digital use and most print applications
• SVG: Best for scaling to any size without quality loss
• PDF: Good for professional printing
• EPS: For graphic design applications

6 Design Best Practices

A well-designed QR code balances aesthetics with scannability. Here are the key principles:

Colour Contrast

Maintain a minimum 40% contrast ratio between the foreground and background. Dark patterns on light backgrounds work best. Avoid:

• Yellow on white
• Light grey on white
• Inverted colours (light pattern on dark background)
• Low-contrast colour combinations

Adding Logos

Logos can enhance brand recognition, but follow these rules:

• Use error correction level H (High)
• Keep the logo to 10-15% of the QR code area
• Place it in the centre
• Ensure the logo doesn't overlap finder patterns
• Test thoroughly after adding

Style Variations

Modern QR codes can use various module shapes:

• Square: Classic, highest reliability
• Rounded: Softer, modern appearance
• Dots: Contemporary, eye-catching
• Custom shapes: Unique, but test carefully

Frame and Call-to-Action

Adding a frame with text like "Scan Me" or "Scan for Menu" can increase scan rates by up to 80%. Always tell users what to expect.

7 Size Guidelines

QR code size depends on viewing distance. The general rule is the 10:1 ratio: divide the scanning distance by 10 to get the minimum QR code size.

Minimum Sizes by Application

Print Resolution

For print materials, ensure your QR code is at least 300 DPI. For large-format printing, 150 DPI may suffice due to increased viewing distance.

Quiet Zone

Always maintain a white border (quiet zone) around your QR code equal to at least 4 modules wide. This helps scanners identify the code boundaries.

8 Use Cases by Industry

Hospitality & Restaurants

• Contactless menus
• WiFi access without password sharing
• Table ordering systems
• Feedback/review collection
• Loyalty programme enrolment

Retail & E-commerce

• Product information and specifications
• Price comparison tools
• Reviews and ratings
• Reorder functionality
• Authenticity verification

Healthcare

• Patient check-in
• Prescription information
• Appointment scheduling
• Medical record access
• Medication instructions

Events & Entertainment

• Ticketing and entry
• Event programmes
• Interactive exhibits
• Social media engagement
• Cashless payments

Education

• Supplementary learning materials
• Assignment submissions
• Library resources
• Campus navigation
• Attendance tracking

Real Estate

• Virtual property tours
• Property details and pricing
• Agent contact information
• Neighbourhood information
• Mortgage calculators

Manufacturing & Logistics

• Inventory tracking
• Assembly instructions
• Maintenance schedules
• Supply chain tracking
• Quality control checkpoints

9 Tracking & Analytics

Dynamic QR codes enable detailed tracking. Here's what you can measure:

Key Metrics

• Total Scans: Raw number of times the code was scanned
• Unique Scans: Individual users who scanned (deduped by IP)
• Scan Rate: Scans over time to identify trends
• Geographic Data: Where scans originate (country, city)
• Device Data: iOS vs Android, browser types
• Time Patterns: When users scan (time of day, day of week)

Using UTM Parameters

Add UTM parameters to your destination URLs to track QR code traffic in Google Analytics:

• utm_source=qr_code
• utm_medium=print or digital
• utm_campaign=your_campaign_name
• utm_content=specific_placement

A/B Testing with QR Codes

Create multiple dynamic QR codes pointing to different landing pages to test:

• Different call-to-action text
• Landing page variations
• Placement locations
• Design variations

10 Security Considerations

QR codes themselves aren't inherently dangerous, but they can be exploited. Here's what to know:

Potential Risks

• Phishing: Malicious QR codes can direct users to fake login pages
• Malware: Links to download malicious applications
• QR Code Overlay: Criminals placing fake codes over legitimate ones
• Data Harvesting: Tracking pixels that collect user information

Best Practices for Creators

• Always use HTTPS URLs
• Use a reputable QR code generator
• Regularly check that your codes point to the correct destination
• Use branded short domains for recognition
• Monitor for unusual scan patterns

Best Practices for Scanners

• Preview the URL before visiting
• Be cautious of public QR codes that look tampered with
• Use a scanner that shows the URL first
• Avoid scanning codes from untrusted sources
• Keep your device's security software updated

11 Common Mistakes to Avoid

1. Not Testing Before Printing

Always test your QR code with multiple devices before mass printing. What works on your phone might not work on others.

2. Making It Too Small

Undersized QR codes are the most common cause of scanning failures. When in doubt, go bigger.

3. Poor Colour Contrast

Trendy colour combinations often fail to scan. Stick to dark patterns on light backgrounds.

4. Using Static Codes for Marketing

You'll lose the ability to track ROI and fix errors. Use dynamic codes for any marketing material.

5. Linking to Non-Mobile-Friendly Pages

QR codes are scanned by phones. Ensure your destination is mobile-optimised.

6. No Call-to-Action

A QR code without context gets ignored. Tell users what they'll get when they scan.

7. Overcomplicating the Design

Too many colours, excessive styling, or oversized logos can prevent scanning.

8. Forgetting the Quiet Zone

Crowding other elements right up to the QR code prevents proper scanning.

9. Using Long URLs in Static Codes

Long URLs create dense, harder-to-scan codes. Use URL shorteners or dynamic codes.

10. Not Tracking Performance

Without analytics, you can't measure success or optimise future campaigns.

12 The Future of QR Codes

QR codes have evolved significantly and continue to develop. Here's what's on the horizon:

Emerging Trends

• Payments Dominance: QR-based payments are projected to exceed $5 trillion globally by 2027, particularly in Asia-Pacific markets.
• AR Integration: QR codes increasingly trigger augmented reality experiences, from virtual try-ons to interactive packaging.
• Sustainability: QR codes on products link to recycling instructions, carbon footprint data, and supply chain transparency.
• Healthcare: Digital health passports and medication verification are growing use cases.
• Authentication: QR codes for two-factor authentication and secure access are becoming standard.

Technical Innovations

• Coloured QR Codes: New encoding methods allow full-colour codes with higher data density.
• Animated QR Codes: Dynamic displays that remain scannable while animated.
• Invisible QR Codes: UV-reactive or embedded codes for anti-counterfeiting.
• Secure QR Codes: Encrypted codes that require authentication to decode.

Market Growth

The global QR code market is expected to grow at a CAGR of 16.9% through 2030, driven by contactless payments, digital transformation initiatives, and increased smartphone penetration in developing markets.