QR code technology itself is basically bulletproof. Just look at how to scan a QR code for proof of its simplicity. But, very rarely, there may be an obstacle to scanning the code. That’s trouble. And that’s why we put together this QR code troubleshooting guide.
If you’re unable to scan a QR code or have other general QR code scanning problems, we can help. And if you're here to see what QR code error correction is all about, we can help with that, too.
Read on, fix your problems, and scan away, scanners.
QR Code Scanning Problems
Learning how QR codes work will help you understand QR code issues. Any number of things can be happening when a QR code fails to yield its precious information. Through talking with QR code users and developers, we’ve isolated the five most common points of failure. Being aware of these should make it clear how to fix a QR code if it’s being stubborn.
Color and Contrast
A lot of businesses and brands value form over function. That leads them to some QR code marketing or QR code tracking experimentation for the sake of aesthetic unity with the rest of their branding. Often that means getting creative with their custom QR code’s color or contrast.
QR codes were originally designed to have square black modules on a white background. That is, in turn, what most QR code scanners were designed to read. But any time a QR code flips that dynamic and places lighter squares over a darker background, it can trip some readers up.
Likewise, the QR code may have lighter colors over a darker background, but the difference between the two colors isn’t big enough. There isn’t enough contrast between background and foreground. Think of light blue modules over a dark blue background. This can also cause QR code scanners to fail.
The QR Code Is Too Complex
QR code uses are very numerous. From QR codes in healthcare to QR code food uses. Sometimes they’re used to store quite a bit of information. And sometimes there’s so much information encoded in it, it can’t scan or scans extremely slowly.
This happens with static QR codes. If the phrase “static QR code” is stressing you out, don’t let it. All it means is that the information you get by scanning the QR code is encoded directly in the black and white squares of the QR code itself. That’s opposed to a dynamic QR code, which redirects to a website where the information is accessible.
All that means that the more complex a static QR code’s information, the bigger and more complex the physical QR code has to be. More rows, more columns, more complicated patterns, etc. And if it gets too complicated it can take a long time for your QR code reader to scan it. And sometimes it can’t be scanned at all.
The QR Code Is Blurry or Crooked
Any optical device that scans QR codes requires precise sharpness and definition of the code. Any blurry squares or, crooked rows or columns, or otherwise shoddy formatting or arrangement will wreck the whole thing. That’s why we recommend using a QR code template to properly situate QR codes on tables, windows, doors, and walls.
Your scanning device isn’t great at filling in blanks and recreating parts of inaccessible code. Though it’s getting better. See the QR Code error correction section below. But the most reliable way to scan a code is to make sure the code is in tip-top shape. The entire thing should be crystal clear and well-defined. If it’s not, you’ll have trouble scanning it.
Size and Distance: QR Code Too Small?
Throughout QR code history, they've been smartly been standardized for international usage. That standardization is a size-to distance ratio.
For most current scanning devices, the distance-to-size relationship between a smartphone and its targeted QR code is 10:1. That means a QR code that’s 1 square inch requires the phone be 10 inches away.
So, is the QR code too small? Well, use the above ration. Extrapolate how large or small a QR code should be based on your distance from it. Or how far you should be from a QR code based on the QR code size. Either way, if you’re too far from the 10:1 ratio, you’ll have trouble scanning.
The QR Code is Expired (or the Encoded URL Broken)
QR codes can expire, believe it or not. It’s a function of the business of QR code creation. Companies that professionally create QR codes put expiration dates on them or limit their number of scans. That, of course, generates more revenue for those companies. But it also leaves their customers with a bunch of arbitrary limits, inactive QR codes, and inaccessible QR code PDFs. Whether that’s because the QR code expired at a certain date, the business ran out of monthly scans, or PDF accessibility issues, the QR code will not be functional. And, yes, some companies actually require clients pay them per scan to use the QR codes they generate. Mercifully, that is not something we do with our digital restaurant menu. It’s a low flat free with no expiration and unlimited scans. That makes it a much cheaper, more agile menu strategy than building a menu app.
Or you generated a QR code for a URL and that QR code now redirects to a broken URL. We see this a lot when businesses use a free QR code generator online. It’s sad, but a lot of businesses depend on third-party, fly-by-night websites to create their QR codes for them. And that often involves that website using its own link for redirection. The QR code is effectively useless when that company goes under or can otherwise no longer maintain or guarantee the full operation of that link. Thankfully, we've got a resource to help you find the best QR code generator for you.
If you can’t locate the reason for a QR code’s failure to scan above, it may be your device.
iPhone Won’t Scan QR Code: How to Fix
If your iPhone won’t scan a QR code, here are a few possible reasons why:
- Your Apple device isn’t running iOS 11 or later. If your device is unable to run iOS 11 or later, you can download a third-party app to scan QR codes. You can also update your iOS version.
- Your screen’s brightness is too low. It needs to be bright enough for the camera to see the QR code or the QR code won’t scan.
- Your camera lens has a smudge on it that’s obscuring the camera’s recognition of the QR code. If you don’t, the QR code doesn’t work.
- Your phone is tilted or in any other position than upright. To scan a QR code with an iPhone, your phone must be held vertically.
- Your iPhone may be too close to or too far from the QR code. There’s a sweet spot for the camera to be able to recognize and scan QR codes. It’s when the 10:1 ratio is hit exactly. A good method to find it is to hold your device about a foot from the QR code. Then slowly move in closer to it until it scans.
QR Code Not Working On Android: How to Fix
Here are some reasons why a QR code is not working on Android devices:
- Your Android device isn’t running Android 9 or higher. If your device can’t run Android 9 or higher, you can download a third-party app to scan QR codes. You can also check and update your Android version.
- The screen brightness may be too low. A camera scanning a QR code is just like a camera taking a picture. It needs to be bright enough for the camera to see it.
- There’s a smudge on your camera lens that’s obscuring your camera’s ability to scan and read the QR code. Otherwise, the QR code won’t scan.
- Your device is tilted, crooked, or in a position that’s not upright. QR codes have to be scanned with your phone held vertically. A QR code doesn’t work otherwise.
- Your Android device is possible too close or too far from the QR code. Again, see the 10:1 ratio above. If you’re having trouble finding the right distance, trial and error helps. Move your phone closer and farther until you see the QR code recognized.
If a QR code won’t scan when using iPhone or Android built-in camera apps, try downloading third-party apps. We recommend the Google Lens app for Android or the Google iOS app. Then just run your own QR code test.
QR Code Error Correction: What Is It?
You know what a QR code is, but what is QRcode error correction? Conveniently, a QR code does have the ability to restore data to itself when it’s damaged. It’s called QR code error correction. It’s a mathematical formula that is part of the QR code creation process. And what it does is convert the QR code into a polynomial that can be accessed if the code is damaged. In other words, it’s a mathematical back-up of the visual QR code.
There are four levels of QR error code correction:
- Level L: Able to backup 7% of the QR code’s data
- Level M: Able to backup 15% of the QR code’s data
- Level Q: Able to backup 25% of the QR code’s data
- Level H: Able to backup 30% of the QR code’s data
The level of QR code error correction is chosen when the QR code is created. The reason why all QR codes aren’t created with a level H error correction is because that makes the QR code bigger. The more data that’s being backed up, the more space the QR code needs to devote to storing that data. That means a bigger code with longer load times. And it’s doubly true for backing up complex QR codes. It's one of the best examples of the improvement of QR codes vs. barcodes.
If a QR code won’t scan, it could be because the QR code error correction level is too low for the amount of damage the QR code has sustained. Or it could be that the QR code error correction level is so high—and the original code itself so complex—that the load times are inordinately long.
Unable to Scan QR Code: No Longer!
If you followed this guide from beginning to end, you’re now aware of most of the potential QR code issues. But they’re all pretty rare. They can be created and formatted incorrectly or suboptimally. QR code scanning devices or QR code scanner apps can be misused. QR code error correction levels may be too low or high. Or the QR code may just straight-up be expired or redirecting to a broken website. All QR code issues worth exploring as you troubleshoot your QR experience.
But, at the end of the day, having trouble scanning QR codes is infrequent. QR codes are one of the easiest, least inexpensive, reliable, accessible, and durable restaurant and bar technologies. There are probably 100 other adjectives we could use to describe QR codes—all positive—so deep is our love for them. And that love starts with contactless menus. Not single use menus (see single use menu definition). But 100% contactless menus.
The QR code-based digital restaurant table menuat the leading edge of the touchless restaurant experience. They’re currently helping hundreds of bars, restaurants, and hotels provide germ-free dining experiences while signaling to guests that they take commercial hygiene seriously. And we help those businesses create and roll those digital menus out. Get in touch and we’ll show you exactly how it’s done.