CoderTools

QR Code Generator

Generate custom QR codes for text, URL, WiFi, vCard, email, SMS and more

Select QR Code Type

Text
URL
Email
Phone
SMS
WiFi
vCard

Customization

256px
Square
Rounded
Circular
Extra Rounded
Diamond
Leaf
Dot
Classy

Recommended: Square image, transparent background, max 20% of QR code size

Preview

QR code will appear here

About QR Code Generator

What is a QR Code?

A QR (Quick Response) code is a two-dimensional barcode that can store various types of information. Invented in 1994 by Denso Wave, QR codes are widely used for quick data retrieval using smartphone cameras. They can encode text, URLs, contact information, WiFi credentials, and more.

QR codes were originally designed for the automotive industry in Japan to track vehicle parts during manufacturing. The technology quickly expanded to other industries due to its fast readability and greater storage capacity compared to standard UPC barcodes.

QR codes are defined by the ISO/IEC 18004 international standard, which specifies the technical requirements including symbol structure, data encoding, and error correction algorithms.

Depending on the version and error correction level, a QR code can store up to 7,089 numeric characters, 4,296 alphanumeric characters, 2,953 bytes of binary data, or 1,817 Kanji/Kana characters.

Supported QR Code Types

Each QR code type follows a specific data format standard:

  • Text/Data: Store plain text or any data string
  • URL: Create links to websites that open in browser URL QR codes directly encode the web address. Ensure the URL is complete and valid.
  • Email: Generate MAILTO links with pre-filled subject and body Email QR codes use the MAILTO URI scheme: mailto:[email protected]?subject=Title&body=Content
  • Phone: Create TEL links for direct dialing
  • SMS: Generate text message links with pre-filled content
  • WiFi: Share wireless network credentials for easy connection
    WiFi QR codes use the format: WIFI:T:WPA;S:NetworkName;P:Password;H:false;; where T is encryption type (WPA/WEP/nopass), S is SSID, P is password, and H indicates hidden network.
  • vCard: Store contact information in digital business card format vCard QR codes follow the vCard 3.0 specification (RFC 2426), supporting fields like name, organization, phone, email, and website.

Error Correction Levels

QR codes use Reed-Solomon error correction, allowing them to remain readable even when partially damaged or obscured.

Four error correction levels are available:

  • Level L (Low): ~7% error correction - Best for clean environments with minimal risk of damage
  • Level M (Medium): ~15% error correction - Standard level suitable for most applications
  • Level Q (Quartile): ~25% error correction - Recommended for outdoor use or printed materials
  • Level H (High): ~30% error correction - Ideal when adding logos or expecting potential damage

Higher error correction levels increase data redundancy but also increase the QR code's complexity and size. Choose the appropriate level based on your specific use case.

The Reed-Solomon algorithm divides data into blocks and adds error correction codewords, enabling the QR code to reconstruct missing or corrupted data during the decoding process.

Best Practices

Maintain high contrast between foreground and background colors for optimal scanning

A minimum contrast ratio of 3:1 is recommended. Dark foreground on light background typically works best. Avoid using similar colors or low contrast combinations.

Ensure adequate size - minimum 2x2 cm for print materials

For print: minimum 2x2 cm (0.8x0.8 inches). For digital displays: minimum 150x150 pixels. For billboards or long-distance scanning: scale proportionally based on viewing distance.

Always test generated QR codes with multiple devices and apps

Test with different QR code readers (iOS Camera, Android Camera, dedicated QR apps) to ensure compatibility. Verify functionality in various lighting conditions and angles.

When adding logos, use high error correction and keep logo under 20% of total size

Center logos work best. Use Level H error correction (30%). Ensure the logo doesn't cover critical positioning patterns. Square logos with transparent backgrounds are ideal.

Maintain adequate quiet zone (white space) around the QR code

The quiet zone should be at least 4 modules (squares) wide on all sides. This empty border helps scanners distinguish the QR code from surrounding content.

Use appropriate file formats for different purposes

PNG: Best for web and digital use, supports transparency. SVG: Vector format, perfect for print and scalable designs. Avoid JPEG due to compression artifacts that may affect scannability.

Common Use Cases

Marketing: Product packaging, posters, business cards for quick website access

Link to product information, promotional videos, discount coupons, or social media profiles. Track campaign effectiveness with analytics-enabled URLs.

Payments: Mobile payment systems and cryptocurrency transactions

QR codes enable contactless payments via services like PayPal, Venmo, Alipay, and WeChat Pay. Cryptocurrency wallets use QR codes for secure address sharing.

Authentication: Two-factor authentication and secure login systems

Services like Google Authenticator and Microsoft Authenticator use QR codes to set up time-based one-time passwords (TOTP) for enhanced account security.

Inventory Management: Product tracking and warehouse systems

Track items throughout the supply chain, manage stock levels, and access product details instantly. Integrates with ERP and inventory management systems.

Ticketing: Event tickets, boarding passes, and admission control

Digital tickets with QR codes reduce fraud, enable contactless entry, and provide real-time validation. Widely used in aviation, concerts, sports events, and public transportation.

Education: Link to course materials, attendance tracking, and interactive learning

Teachers can share study materials, homework assignments, and video tutorials. Students can quickly access online resources and submit digital assignments.

Healthcare: Patient identification, medication tracking, and medical records access

Hospitals use QR codes for patient wristbands, prescription labels, and linking to electronic health records, improving accuracy and reducing errors.

Technical References & Resources

ISO/IEC 18004:2024

Official QR Code specification defining symbol structure, encoding, and error correction

QR Code - Wikipedia

Comprehensive overview of QR code history, technology, and applications

Denso Wave - QR Code Developer

Official website of QR code inventor with technical documentation and specifications

vCard 3.0 Specification (RFC 2426)

Standard format for electronic business cards used in vCard QR codes

WiFi QR Code Format

ZXing documentation on WiFi network configuration QR code format