We recommend a size of 2 x 2 cm for a QR Code
A QR Code that encodes up to 72 characters (which is the length of a typical URL) should be printed in minimum size of 20×20 mm (0.79x0.79″) when scanned from a distance of 20cm (7.9″)
Consider the scanning distance
Rule of the thumb: the ratio between scanning distance and the QR Code size is 10:1. So if you want to scan a QR Code from 10 meters (390″), the size of the QR Code should be 1 square meter (39″). Or if you print a QR Code on a post card, the user will scan the QR Code from a distance close to 15cm (5.9″). Applying the rule the QR Code may have a minimum size of 15mm (0.59″).
| Surface | Scan distance | QR Code size |
|---|
| A4 e.g. Magazine | 20cm | 20mm x 20mm |
| A3 e.g. Poster | 1m | 100mm x 100mm |
| 3x4m e.g. Billboard | 10m | 1m x 1m |
Consider the number of characters encoded in the QR Code
The more characters you are using in a QR Code the more complex the structure is and the harder the QR Code can be read. In most of the cases people use a QR Code to forward people to a website or landing page. The average length of an URL based on all QR Codes from our plattform is 60 characters, which is safe to print a QR Code in the size of 2 x 2 cm.
Smaller sizes of 1 x 1 cm are possible on modern smartphones with a camera that supports autofocus. However, you should print them in a size that works for most users under all different contexts.
How to print your QR Code as small as possible
Use scalable vectorized QR Codes
It is important create QR Codes in Vector format. If you are plotting QR Codes from a .png or .jpg source, they may get blurred and cannot be read anymore.
Use vector QR Code to avoid blurring or pixelationUse low Error Correction Level
When creating a QR Code you can set an Error Correction Level. The higher the level is set, the more of a QR Code may be destroyed while the QR Code will be still readable. However, a higher level also increases the size of a QR Code. We recommend setting the error level L for QR Codes without an embedded logo. This will give you the smallest possible size of a QR Code.
Mind the quiet zone around the QR Code
If you print a QR Code always leave a quiet zone (margin) around the QR Code. We recommend having 4 units of white space around your QR Code to ensure it can be read by any QR Code reader.
Use shortened URLs
How much information do you want to store in the QR Code? The less the better. Use shortened URLs instead of a long URL. The shorter the URL the less units a QR Code will contain and there for can be plotted smaller.
A shortened URL with up to 17 characters will produce a QR Code with 21×21 units. Encoding a longer URL with up to 72 chars will result in a QR Code with 35×35 units.
(2) A shorted URL: https://qr.vc/123Devices that scan very small QR Codes
A few years ago, we organized a experiment to determine which devices had the best scanning capabilities. The participants had to download a sample of different sized QR Codes and print it out. The results that we obtained demonstrated that the following devices we able to scan QR Code as small as 4mm x 4mm! Please note that these was just a test with perfect conditions - the QR Codes were black and white with no logo and had less then 20 characters encoded.
< 4mm (0.16”)
- Huawei Ascend XT H1611 (3mm QR Code was printed on a Canon MF4320 laser printer with 600dpi)
< 5mm (0.19”)
- Apple iPhone 5+
- Google Nexus 5+
- HTC One
- Huawei Ascend Mate 7+
- LG D802, D959
- MicroMax Q450
- Nokia Lumia 635
- OnePlus One
- Samsung GALAXY ACE 3+, GALAXY Note 4 Edge, GALAXY S4, GT-I9500, SGH-I317