Learn QR Codes
Whether you're scanning your first code or deploying enterprise-grade QR campaigns, this resource hub covers every concept, strategy, and technical detail you need.
Core Topics
Frequently Asked Questions
Direct, expert answers to the most common questions about QR codes.
What is the minimum size for a printable QR code?
The absolute minimum is 2 cm × 2 cm (approx. 0.8 in) for a scanning distance of up to 20 cm. For posters or larger print materials, scale up proportionally. Always maintain the quiet zone (4-module white border) regardless of size.
How many characters can a QR code hold?
It depends on version and error correction level. A Version 40-L code holds 7,089 numeric characters, 4,296 alphanumeric characters, or 2,953 bytes of binary data. For practical marketing use (URLs), a Version 5 code is usually sufficient.
Can I change a QR code after printing?
Only if you use a dynamic QR code. Dynamic codes encode a short redirect URL; the actual destination can be updated any time in your dashboard. Static codes permanently encode the data — once printed, they cannot be changed.
Do QR codes expire?
Static QR codes never expire — they work as long as the encoded URL is live. Dynamic QR codes remain active as long as your account subscription is active. TheQrify's free-tier codes do not have an artificial expiry date.
What error correction level should I use with a logo?
Always use Level H (30%) when placing a logo inside a QR code. This allows up to 30% of the code surface to be covered while still remaining fully scannable. Using Level L or M with a logo significantly increases scan failure rates.
Why is my QR code not scanning?
Common causes: (1) Quiet zone is cropped, (2) insufficient contrast between foreground and background colours, (3) logo is too large and exceeds the error correction threshold, (4) the encoded URL has changed or is offline, (5) the code was saved at too low a resolution (use SVG for print).
Are coloured QR codes safe to use?
Yes — as long as the contrast ratio between the module colour and the background is at least 3:1. Dark colours on a white background are always safest. Never use a light foreground colour on a light background, even if they appear distinct to the human eye.
How do I track how many people scanned my QR code?
Use a dynamic QR code and connect your destination URL with UTM parameters (e.g., utm_source=flyer&utm_campaign=spring-sale). Dynamic codes also provide built-in scan analytics including date, device type, and approximate location.
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