What is QR Code?
A QR code (Quick Response code) is a two-dimensional barcode that can store URLs, text, contact information, Wi-Fi credentials and more. It is scanned by smartphone cameras and is widely used in marketing, payments and contactless interactions.
Common Uses for QR Code
- Website and landing page links
- Digital business cards (vCard)
- Restaurant menus and Wi-Fi login
- Product packaging linking to manuals
Static vs Dynamic QR Codes
A static QR code stores its data directly in the code pattern, so it never expires and needs no subscription - but you can't change the destination once printed. A dynamic QR code stores a short URL that redirects, letting you edit the target and track scans, but it depends on a service that can stop working. For batch printing and long-term use, static QR codes are the safest and most cost-effective choice.
QR Code Error Correction Levels
QR codes have four error-correction levels (L, M, Q, H). Level L tolerates about 7% damage, level H about 30%. Higher levels make the code denser but more durable - useful when the code will be printed on curved surfaces or partly covered. This generator produces robust codes that scan reliably in normal use.
What Makes a QR Code Unscannable
The most common reasons a QR code won't scan: not enough white quiet space around it, low contrast (e.g. light bars on a light background), the code is printed too small, or it's stretched or distorted. Keep a white margin around the code, print it at least 2cm wide, and use dark modules on a light background.
QR Code Versions and Symbol Size
QR codes come in 40 versions: version 1 is a 21x21 module grid and each step up adds four modules per side, up to 177x177 at version 40. More data means a higher version and a denser symbol. For print, the practical sweet spot is the lowest version that fits your data - a short URL at version 3-5 prints cleanly at 20mm, while a long vCard may need 30mm or more to stay reliably scannable.
Putting a Logo in the Middle of a QR Code
Because QR error correction can rebuild damaged data, a small centre logo often still scans - but it shrinks your safety margin. If you overlay a logo, use error-correction level H (30% recovery), keep the logo under about 20% of the code area, never cover the three finder squares in the corners, and test-scan with several phones before printing. This generator produces clean codes without logos; add branding in your design tool afterwards and test.
Reference