Quick response (QR) codes have become increasingly popular in recent years as an easy way to encode information that can be quickly scanned by a smartphone camera. However, sometimes QR codes don’t scan properly which can be frustrating if you are trying to access information or a website.
What is a QR code?
A QR code is a type of barcode that can be scanned by a smartphone camera and decoded by QR reader apps. The code consists of black and white squares arranged in a square pattern on a white background. The squares represent binary code that encodes data such as text, URLs, contact information, Wi-Fi passwords, and more. When scanned by a smartphone, the data encoded in the QR code can be extracted and displayed on the phone screen.
Why won’t my QR code scan?
There are several common reasons why a QR code may fail to scan properly:
The code is damaged or obscured
For the QR code to scan correctly, the camera needs to be able to clearly see the entire code. If part of the code is covered up, folded, torn, or obscured in any way, it likely won’t scan properly. This includes codes that are wrinkled, dirty, scratched, or faded. The QR code needs to be completely visible and intact.
The code is too small
QR codes can only be shrunk down to a certain minimum size before they become unscannable. The smallest recommended size for a scannable code is about 1 inch by 1 inch. Any smaller and a smartphone camera will likely have trouble focusing on the code and reading it accurately.
There is insufficient contrast
The contrast between the black and white squares in the code needs to be high for the code to scan properly. QR codes printed in grayscale or with insufficient contrast between the light and dark areas may not scan well. For best results, the QR code should be printed in high contrast black and white only.
There is glare on the code
Glare from light sources shining directly on the QR code can prevent a proper scan. The scanner may have trouble differentiating between the light and dark areas. Try scanning in lower light conditions or from an angle to reduce glare on the code surface.
The code is too far away
Most smartphone cameras can only focus properly on QR codes from a distance of 3-12 inches. Trying to scan from too far away will likely result in a blurry, out-of-focus image that cannot be properly interpreted. Move your phone closer to the code until it is clear in the camera viewfinder.
The scanner app is poor quality
Not all QR scanner apps provide the same level of accurate scanning capabilities. Poor quality apps may fail to scan codes that can be read by superior scanner apps. If one app is having trouble, try scanning the code with different scanner apps to determine if the issue is with the app or the code itself.
The code contains errors
Mistakes can occur when QR codes are generated that prevent them from scanning correctly. If the same code will not scan across multiple scanner apps and devices, it likely contains errors in the encoding that render it unreadable. The code will need to be regenerated to resolve such issues.
How to fix an unscannable QR code
If your QR code is failing to scan, there are steps you can take to troubleshoot and fix the issue:
Check the physical condition of the code
Examine the code closely and look for any damage, markings, creases, or other degradation that could affect scannability. If the issue is physical, you will need to replace the damaged code with a fresh one.
Try cleaning the code
Gently wipe off any dirt, grime, or substances covering the code with a microfiber cloth. Avoid using liquids which could further damage the code.
Increase the size of the code
If the code is smaller than one inch square, try regenerating it at a larger size for better scanning.
Improve contrast
For printed codes with insufficient contrast, try adjusting print settings, changing paper type, or printing with a higher quality printer if available to boost contrast.
Minimize glare
Experiment with scanning from different angles, under shade, or indoor light to reduce glare on the code surface.
Use multiple scanner apps
If one scanner has trouble, try a few others which may have better scanning capabilities needed for your particular code.
Move phone closer
Position phone within 3-12 inches when scanning and allow camera to focus on code clearly.
Regenerate the code
If the code has inherent errors, recreate the QR code using a trusted QR generator app or website.
Try a different device
In rare cases, the camera or scanner software on a particular device may have trouble scanning codes that work fine on other devices. Test scanning the code with a different smartphone if available.
Tips for creating scannable QR codes
Follow these tips when generating QR codes to ensure optimal scannability:
- Use a recommended size of at least 1 inch by 1 inch.
- Choose high resolution printing for sharp image quality.
- Print codes in high contrast black and white only.
- Avoid placing codes on backgrounds with patterns or colors.
- Leave a quiet zone of white space around code.
- Use a high quality QR generator app or website.
- Double check encoded data for errors before printing.
- Consider having codes professionally printed for durability.
- Laminate printed codes to protect from wear and tear.
- Regenerate new codes as soon as damage occurs.
Common QR code uses
Here are some of the most popular uses for scannable QR codes:
| QR Code Use | Example |
|---|---|
| Website URLs | Encodes a URL that directs scanner to visit a website |
| Contact information | Stores contact details like phone numbers, emails, addresses |
| Product links | Takes scanner directly to product page to purchase or learn more |
| Event details | Shares event time, location, registration links |
| Coupons/discounts | Redeem coupon codes and special offers |
| Social media profiles | Link to Instagram, Facebook, Twitter, YouTube, etc. |
| WiFi login | Connects devices to WiFi by scanning code instead of entering password |
| Boarding passes | Stores flight booking details for digital check-in and boarding |
| Payments | Initiate payments by scanning codes linked to payment apps |
Conclusion
When utilized properly, QR codes provide a fast, convenient way to share information by simply scanning a code. However, issues like damage, size, glare, anderrors can prevent codes from scanning correctly. Troubleshooting scanning problems involves checking the physical condition of the code, trying multiple scanners, adjusting distance and angles, and regenerating a new code if necessary. Following best practices for QR code size, contrast, and generation will help avoid scanning issues. With billions of scans per year, QR codes show no signs of slowing down as an ubiquitous information sharing tool when properly created and maintained.