QR Code Types & Formats: Complete Technical Guide

Not all QR codes are created equal. The code that opens a website uses completely different encoding than one storing contact information. Understanding these differences ensures your codes work reliably and efficiently.

QR Code Basics: How They Work

Before diving into types, understand the fundamental structure:

Anatomy of a QR Code

Positioning Patterns (3 large squares in corners)

• Help scanners locate and orient the code
• Always present in same locations
• Critical for quick detection

Alignment Patterns (smaller squares in grid)

• Help with perspective correction
• More patterns in larger codes
• Enable accurate scanning at angles

Timing Patterns (alternating line between position markers)

• Coordinate system for data location
• Helps determine QR version
• Ensures accurate module reading

Format Information

• Error correction level
• Mask pattern used
• Located near position patterns

Data and Error Correction

• Actual encoded information
• Redundancy for damage recovery
• Takes up majority of code

Quiet Zone (white border)

• Minimum 4 modules wide
• Separates code from surroundings
• Essential for reliable scanning

Version and Capacity

QR Code Versions: 1 through 40

Version 1:

• Size: 21×21 modules
• Capacity: 25 alphanumeric characters
• Use: Short URLs, simple data

Version 10:

• Size: 57×57 modules
• Capacity: 174 alphanumeric characters
• Use: Medium data, contact cards

Version 40:

• Size: 177×177 modules
• Capacity: 4,296 alphanumeric characters
• Use: Large data sets, documents

Automatic Selection: Most generators choose version based on data length.

Data Encoding Modes

Different character types encode differently, affecting capacity:

Numeric Mode

What It Encodes: Numbers only (0-9)

Capacity (Version 40, Low error correction):

• Maximum: 7,089 digits
• Example: "1234567890"

Use Cases:

• Serial numbers
• Phone numbers
• Tracking codes
• Numeric IDs

Efficiency: Most efficient encoding

• 3.33 bits per digit
• Smallest QR code for numeric data

Example:

Input: "123456789012"
Mode: Numeric
Result: Version 1, 21×21 modules

Alphanumeric Mode

What It Encodes: Numbers, uppercase letters, and symbols

• Characters: 0-9, A-Z
• Symbols: space, $, %, *, +, -, ., /, :

Capacity (Version 40, Low error correction):

• Maximum: 4,296 characters
• Example: "HELLO WORLD 123"

Use Cases:

• URLs (uppercase)
• Product codes
• Short messages
• Identification strings

Efficiency:

• 5.5 bits per character
• More efficient than byte mode for supported characters

Limitation: Case-sensitive text not supported

Example:

Input: "HTTPS://EXAMPLE.COM"
Mode: Alphanumeric
Result: Version 2, 25×25 modules

Byte Mode

What It Encodes: Any 8-bit data

• All ASCII characters
• Unicode (UTF-8)
• Binary data

Capacity (Version 40, Low error correction):

• Maximum: 2,953 bytes
• Example: "Hello World!" (mixed case)

Use Cases:

• Full URLs with mixed case
• Email addresses
• Multilingual text
• Binary data

Efficiency:

• 8 bits per byte
• Least efficient for simple text
• Necessary for complex data

Example:

Input: "hello@example.com"
Mode: Byte (mixed case)
Result: Version 2, 25×25 modules

Kanji Mode

What It Encodes: Japanese Kanji characters

Capacity (Version 40, Low error correction):

• Maximum: 1,817 characters
• Specific to Shift JIS encoding

Use Cases:

• Japanese text
• Kanji-specific applications

Efficiency:

• 13 bits per character
• More efficient than Byte mode for Kanji
• Optimized for Japanese language

Choosing the Right Mode

Optimization Strategy:

1. All numeric? → Numeric mode
2. Uppercase + limited symbols? → Alphanumeric
3. Mixed case or special characters? → Byte mode
4. Japanese Kanji? → Kanji mode

Example Comparison:

Data: "HTTPS://EXAMPLE.COM"

Alphanumeric mode:
- Version 1 (21×21)
- 19 characters

Byte mode (if lowercase used):
- Version 2 (25×25)
- Larger code for same data

Choice: Alphanumeric (smaller, faster scan)

Error Correction Levels

QR codes include redundancy to remain scannable even when damaged:

Level L (Low): ~7% Recovery

Damage Tolerance: Up to 7% of code can be damaged

Data Capacity: Maximum (least redundancy)

Use Cases:

• Controlled environments
• Digital displays
• Protected printing
• Maximum data needs

Example:

Version 10, Level L
Capacity: 174 alphanumeric characters
Damaged area: Up to 7%

When to Use:

• ✅ Indoor use
• ✅ Clean surfaces
• ✅ Need maximum capacity
• ❌ Outdoor exposure
• ❌ Rough handling

Level M (Medium): ~15% Recovery

Damage Tolerance: Up to 15% of code can be damaged

Data Capacity: Good balance

Use Cases:

• General purpose
• Product packaging
• Indoor posters
• Business cards

Example:

Version 10, Level M
Capacity: 135 alphanumeric characters
Damaged area: Up to 15%

When to Use:

• ✅ Most applications (default choice)
• ✅ Normal wear and tear expected
• ✅ Standard printing quality
• ✅ Moderate data needs

Level Q (Quartile): ~25% Recovery

Damage Tolerance: Up to 25% of code can be damaged

Data Capacity: Reduced for reliability

Use Cases:

• Outdoor advertising
• Rough surfaces
• Long-term exposure
• Logo overlay desired

Example:

Version 10, Level Q
Capacity: 95 alphanumeric characters
Damaged area: Up to 25%
Logo overlay: Possible

When to Use:

• ✅ Logo in center (takes up space)
• ✅ Outdoor use
• ✅ Industrial environments
• ✅ Weather exposure

Level H (High): ~30% Recovery

Damage Tolerance: Up to 30% of code can be damaged

Data Capacity: Minimum (maximum redundancy)

Use Cases:

• Harsh environments
• Custom designs
• Large logo overlays
• Critical applications

Example:

Version 10, Level H
Capacity: 74 alphanumeric characters
Damaged area: Up to 30%
Logo overlay: Up to 30% coverage

When to Use:

• ✅ Maximum reliability critical
• ✅ Artistic/branded designs
• ✅ Severe conditions
• ❌ When capacity is priority

Choosing Error Correction Level

Decision Matrix:

| Factor | L | M | Q | H | |--------|---|---|---|---| | Indoor clean | ✅ | ✅ | ⚠️ | ❌ | | Outdoor | ❌ | ⚠️ | ✅ | ✅ | | With logo | ❌ | ⚠️ | ✅ | ✅ | | Max data | ✅ | ✅ | ❌ | ❌ | | Print quality varies | ❌ | ✅ | ✅ | ✅ |

Default Recommendation: Level M (best balance for most uses)

QR Code Data Types

Different information types use specific formats:

URL/Website Links

Standard Format:

https://www.example.com

Optimization:

• Use HTTPS (security and trust)
• Shorten URLs when possible
• Remove unnecessary parameters
• Use URL shorteners for long links

Example:

Long URL (87 characters):
https://www.example.com/products/category/subcategory/item?utm_source=qr&ref=12345

Shortened (22 characters):
https://bit.ly/abc123

Result: Smaller QR code, faster scanning

Mobile Optimization:

• Ensure mobile-responsive landing page
• Fast loading (under 3 seconds)
• Clear call-to-action
• Easy navigation

WiFi Network Configuration

Format:

WIFI:T:WPA;S:NetworkName;P:Password;H:false;;

Parameters:

• T: Network type (WPA, WEP, or leave blank for open)
• S: SSID (network name)
• P: Password
• H: Hidden network (true/false)

Example:

WIFI:T:WPA;S:CoffeeShop_Guest;P:coffee123;H:false;;

Use Cases:

• Restaurant/cafe guest WiFi
• Office guest networks
• Event WiFi access
• Hotel rooms

Best Practices:

• Use WPA2 or WPA3
• Avoid special characters in SSID
• Test on multiple devices
• Display network name visibly

Contact Information (vCard)

Format:

BEGIN:VCARD
VERSION:3.0
FN:John Doe
ORG:Company Name
TEL:+1-555-123-4567
EMAIL:john@example.com
URL:https://example.com
END:VCARD

Full Example:

BEGIN:VCARD
VERSION:3.0
N:Doe;John;;;
FN:John Doe
ORG:Acme Corporation
TITLE:Marketing Director
TEL;TYPE=WORK,VOICE:+1-555-123-4567
TEL;TYPE=CELL:+1-555-987-6543
EMAIL:john@example.com
URL:https://johndoe.com
ADR;TYPE=WORK:;;123 Main St;New York;NY;10001;USA
END:VCARD

Fields:

• Name (FN, N)
• Organization (ORG)
• Title (TITLE)
• Phone numbers (TEL)
• Email (EMAIL)
• URL (URL)
• Address (ADR)
• Photo (PHOTO) - base64 encoded

Size Optimization:

• Include only essential fields
• Shorter job titles
• Minimal address details
• Skip photo for smaller code

Email Messages

Format:

mailto:email@example.com?subject=Subject&body=Message

Parameters:

• to: Recipient email
• subject: Pre-filled subject
• body: Pre-filled message
• cc: CC recipients
• bcc: BCC recipients

Example:

mailto:support@example.com?subject=Product%20Inquiry&body=I%20would%20like%20to%20know%20more%20about

Use Cases:

• Customer support links
• Product inquiries
• Feedback forms
• Newsletter signups

URL Encoding: Use %20 for spaces, %0A for line breaks

SMS Messages

Format:

sms:+15551234567?body=Message text here

iOS Format:

sms:+15551234567&body=Message text here

Cross-Platform (works on both):

sms:+15551234567?body=Message

Example:

sms:+15551234567?body=I%27d%20like%20to%20schedule%20an%20appointment

Use Cases:

• Appointment reminders
• Contest entries
• Text-to-join campaigns
• Customer feedback

Phone Numbers

Format:

tel:+15551234567

Best Practices:

• Include country code (+1 for US)
• No spaces or dashes
• Use E.164 format

Examples:

US: tel:+15551234567
UK: tel:+442012345678
International: tel:+[country][number]

Geographic Coordinates

Format:

geo:37.7749,-122.4194

With Query:

geo:0,0?q=37.7749,-122.4194(Label)

Example:

geo:40.7128,-74.0060?q=40.7128,-74.0060(New York City)

Opens:

• Google Maps (Android)
• Apple Maps (iOS)
• Default mapping app

Use Cases:

• Event locations
• Store finders
• Real estate listings
• Tourism guides

Calendar Events

Format:

BEGIN:VEVENT
SUMMARY:Event Name
DTSTART:20250201T100000Z
DTEND:20250201T110000Z
LOCATION:123 Main St, City
DESCRIPTION:Event details here
END:VEVENT

Example:

BEGIN:VEVENT
SUMMARY:Team Meeting
DTSTART:20250215T140000Z
DTEND:20250215T150000Z
LOCATION:Conference Room A
DESCRIPTION:Monthly team sync
URL:https://zoom.us/j/123456
END:VEVENT

Use Cases:

• Conference schedules
• Appointment reminders
• Event invitations
• Webinar registrations

Static vs. Dynamic QR Codes

Static QR Codes

Characteristics:

• Data embedded directly in code
• Cannot be changed after creation
• No tracking capabilities
• Works forever (no expiration)
• No internet required for code to work

Pros:

• ✅ Free to create
• ✅ Never expires
• ✅ No dependencies
• ✅ Privacy-friendly
• ✅ Offline functionality

Cons:

• ❌ Cannot update destination
• ❌ No analytics
• ❌ Larger code for long URLs
• ❌ No A/B testing

Best For:

• Permanent uses (business cards)
• WiFi passwords
• Contact information
• When tracking not needed
• Privacy-conscious applications

Example:

QR contains: https://example.com/page
Scans to: https://example.com/page (always)
If page moves: QR code becomes invalid

Dynamic QR Codes

Characteristics:

• Short redirect URL in code
• Actual destination can be changed
• Analytics and tracking
• Requires internet connection
• Depends on redirect service

Pros:

• ✅ Update destination anytime
• ✅ Detailed analytics
• ✅ A/B testing possible
• ✅ Smaller QR code (short URL)
• ✅ Campaign management

Cons:

• ❌ Requires redirect service
• ❌ Service dependency (can expire)
• ❌ Usually costs money
• ❌ Privacy considerations
• ❌ Slower (extra redirect)

Best For:

• Marketing campaigns
• Print advertising
• Event materials
• Testing and optimization
• When analytics essential

Example:

QR contains: https://qr.service/abc123
Initially redirects to: https://example.com/spring-sale
Later changed to: https://example.com/summer-sale
Same QR code works for both

Decision Guide

Choose Static When:

• Information won't change
• Tracking not required
• Want maximum reliability
• Long-term use (years)
• Privacy important

Choose Dynamic When:

• Campaign testing needed
• Analytics required
• URL might change
• Short-term campaigns
• Multiple destination testing

Advanced QR Code Features

Micro QR Codes

Specifications:

• Smaller size than standard QR
• Single position marker
• Versions: M1 to M4
• Limited capacity

Capacity:

• M1: 5 numeric digits
• M2: 10 alphanumeric characters
• M3: 23 alphanumeric characters
• M4: 35 alphanumeric characters

Use Cases:

• Small items (jewelry, electronics)
• Space-constrained applications
• Component tracking
• Minimal data needs

Frame QR Codes

Features:

• Custom canvas around code
• Brand integration
• Call-to-action text
• Eye-catching designs

Examples:

• "Scan Me" speech bubble
• Product image frame
• Brand color borders
• Decorative patterns

Considerations:

• Don't violate quiet zone
• Maintain scannability
• Test thoroughly
• Balance design and function

Frequently Asked Questions

What's the maximum data capacity of a QR code?

Version 40 with Level L can hold 7,089 numeric digits, 4,296 alphanumeric characters, or 2,953 bytes.

Which error correction level should I use?

Level M for most uses. Level Q or H if adding logos or for outdoor use. Level L only for controlled environments.

Can I edit a QR code after printing?

Only dynamic QR codes allow changing the destination. Static codes cannot be modified after creation.

Do different data types affect QR code size?

Yes. Numeric mode is most efficient, followed by alphanumeric, then byte mode. Same data requires larger codes in less efficient modes.

How do I make the smallest possible QR code?

Use numeric or alphanumeric mode, Level L error correction, shorten URLs, and include only essential data.

What happens if I exceed capacity?

The QR code automatically increases to the next version. More data = larger code.

Conclusion

Understanding QR code technical specifications ensures reliable, optimized codes for any use case. Choose the right encoding mode, error correction level, and data type for your specific needs.

Technical Optimization Checklist:

• ✅ Choose appropriate encoding mode
• ✅ Select right error correction level
• ✅ Optimize data format
• ✅ Test across devices
• ✅ Verify quiet zone
• ✅ Use appropriate version

Ready to create optimized QR codes? Generate QR Codes →

---

Learn practical applications in our QR Code Marketing Guide and QR Code Design Best Practices.