QR Code Generator

A QR code (Quick Response code) is a two-dimensional matrix barcode invented in 1994 by Denso Wave, a Toyota subsidiary. Unlike traditional barcodes that store data in one dimension, QR codes use a grid of black and white squares to encode information both horizontally and vertically.

QR codes can store up to 7,089 numeric characters or 4,296 alphanumeric characters. They include built-in error correction, allowing them to remain readable even when partially damaged or obscured.

The three large squares in the corners are position detection patterns that help scanners quickly locate and orient the code. The smaller patterns throughout the code contain alignment, timing, and data information.

Level L (Low): Can recover approximately 7% of data. Produces the least dense QR code, ideal for clean digital displays where damage is unlikely.

Level M (Medium): Can recover approximately 15% of data. A good balance between density and resilience, suitable for most general-purpose applications.

Level Q (Quartile): Can recover approximately 25% of data. Recommended for printed materials that may experience some wear or partial obstruction.

Level H (High): Can recover approximately 30% of data. Best for industrial environments or when a logo is placed over part of the QR code.

Website URLs: The most common use. Scanning the QR code opens a webpage directly in the user's browser, eliminating the need to type long URLs.

Contact information (vCard): QR codes can encode full contact details including name, phone, email, and address. Scanning adds the contact to the phone directly.

Wi-Fi credentials: Share Wi-Fi network name and password without dictating complex passwords. The phone connects automatically after scanning.

Payment and tickets: Mobile payment systems, boarding passes, event tickets, and loyalty programs all use QR codes for fast, contactless transactions.

Traditional barcodes (1D) store 20-25 characters in a single row of varying-width lines. They require a line-of-sight scanner and can only encode numbers or simple text.

QR codes (2D) store up to 7,089 characters in a matrix grid. They can be scanned from any angle, at various distances, and with standard smartphone cameras.

QR codes include built-in error correction, making them far more resilient to damage. Barcodes become unreadable with even minor scratches or smudges.

For simple product identification, barcodes remain efficient. For linking to digital content, sharing complex data, or consumer-facing applications, QR codes are the standard.

Ensure sufficient contrast between the foreground and background colors. Black on white provides the best scan reliability. Avoid low-contrast color combinations.

Use an appropriate size: the minimum recommended size for printed QR codes is 2 cm x 2 cm (0.8 in x 0.8 in). Larger codes scan more reliably at greater distances.

Test your QR code with multiple devices and scanning apps before distributing it. Different cameras and lighting conditions can affect readability.

For printed materials, use a higher error correction level (Q or H) to account for potential wear, folding, or partial obstruction.

QR codes can be used for phishing: a malicious QR code could redirect to a fake website. Always verify the URL after scanning before entering any personal information.

Dynamic QR codes (where the destination URL can be changed) add a layer of risk since the destination can be modified after the code is distributed.

Never scan QR codes from untrusted sources, especially those placed over other QR codes (a common attack vector in public spaces).

For sensitive applications, consider using a URL shortener you control so you can monitor and disable links if compromised.