QR Codes have now become a well-known technology. All thanks to the increase in smartphone penetration and access to high-speed internet. From pharmaceuticals to warehouses, they are being used everywhere.

And like every technology, QR Codes work only when used right. So you want to make sure that you don’t make any mistakes with them. After all, you won’t like to be stuck with an invalid QR Code.

Here’s the thing—while it’s natural to make mistakes, some best practices can help you avoid them.

Hence, you’re looking for a checklist of some common invalid QR Code scenarios and their solutions. It’ll help you stay informed and make sure you don’t repeat the most common mistakes.

This article has an exhaustive list of common issues that make your QR Code invalid and their solution.

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A. The most common mistakes that render a QR Code invalid

1. Selecting an inverted color scheme

High contrast between the QR Code and its background is very important for its scannability. Hence, deciding on the right color scheme is very crucial.

For example, if your QR Code is dark in color, the background should be white. And you can also go for vice-versa. However, there’s a problem. The negative color scheme (light QR Code on dark background) doesn’t work for some scanners.

While some scanners can scan them perfectly well, others struggle to do so.


Its solution is quite simple. Always select a dark QR Code on a light background as much as possible. A negative color theme must be avoided unless necessary.

In case it is required, then ensure that the background is sufficiently dark colored for a light QR Code. This can ensure high scannability.

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2. Over-customization

QR Codes are most commonly used for marketing and many other customer-facing roles. And for that, it’s recommended that you add design to your QR Codes. It makes your QR Code visually appealing and attracts more scans.

You can do it by adding a logo and colors to them. Or by adding an image as their background.

But as they say—excess of anything can be harmful. And this holds true for customization too.

For example, say you customize a QR Code to such an extent that the contrast between QR Code and its background becomes dull. Or you customize it in a way that its data modules become unclear for the scanners to recognize.

Such mistakes can make the QR Code unreadable for the scanners and, hence, invalid.


You must design the QR Codes by blending the right colors while ensuring high contrast. It will instantly help the scanners differentiate the QR Code and its background for better scannability. In addition, don’t over-customize the rest of the elements either.

Remember that when it comes to design, less can often be more!

Custom QR Codes

3. Selecting the wrong download format

Are you planning to add the QR Code on print media creatives? Then you must make sure that you don’t go for the wrong image formats.

Many users simply choose any image format and dimensions without giving it a second thought. For example, say you want to use a QR Code for billboards and you download images in PNG format.

There is a high chance that when you add the QR Code billboard and resize it, it’ll get pixelated. And for a scanner to work well, each element of the QR Code be clear and tidy. A pixelated QR Code mostly does not scan.

Now you wouldn’t want that, right?


You must select the right image format and dimensions as per your use case. If you are planning to use QR Codes on print media, go for vector formats such as SVG, EPS, and PDF. These formats don’t pixelate no matter how much resizing is done.

On the other hand, if you are going to use them for digital displays, you can go for raster formats such as PNG, JPEG, and JPG.

4. Inappropriate QR Code size and scanning distance

The size of the QR Code and its distance from the scanner is important for its scannability.

Both size and scanning distance are mutually dependent on each other. For example, the size of the QR Code placed on a billboard to be scanned meters will have to be fairly large. Conversely, the size of a QR Code on a product packaging to be scanned from a few centimeters can be way smaller.

Not taking these factors into account is one of the most common mistakes that render QR Codes non-functional.


Depending on how far the users be, you can calculate the right size of the QR Code. You just need to follow a simple mathematical rule.

It says that the ratio of scanning distance to the QR Code’s size should be close to 10:1. That means if a QR Code is to be scanned from 100 cm away, it must be at least 10 cm wide.

To know more about the exact formulas and calculations, you can refer to this detailed guide.

5. Encoding wrong content

Another mistake one can do is encoding the wrong content in the QR Code. For example, say you have created a QR Code to drive web traffic to your website. But accidentally, you add the wrong or non-functional URL during QR Code creation.

But when users scan it, they will not be taken to any website and may see a ‘404 error’ message. This will not only harm your business but also customers’ experience.


Always check the data you enter in the QR Code. Even a small typo in the URL can make the QR Code invalid or non-functional.

6. Using expired QR Code

Do you know QR Codes are of two types—static and dynamic?

Static QR Codes store the content directly. That means they remain functional forever. Also, once generated, you can’t change the encoded content.

On the other hand, dynamic QR Codes don’t store the content directly. They store a redirecting URL that stores the target content. This redirecting URL is assigned by the QR Code generator. Hence, dynamic QR Codes can be edited anytime and need an ongoing subscription.

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This means you need an ongoing subscription with your QR Code service provider to keep the dynamic QR Code active.

Although you need a subscription, dynamic QR Codes are still a better choice. That’s because dynamic QR Codes are editable and trackable. This means you can edit the encoded content anytime you want without the need to recreate them.

Moreover, you can monitor its performance. For example, you can see the following data:

  • How many people have scanned the QR Code
  • Where did they scan it
  • When did they scan it
  • Which browser do they use to scan it

Besides, they also give you valuable insights into how your end-users interact with the encoded content after scanning the QR Code. This can be anything such as a button for registration or sign-up.

All these features are exclusive to dynamic QR Codes only. Hence, if you’re planning to create one, consider a dynamic QR Code. Also, advanced benefits such as GPS location tracking, password protection, and lead generation, make dynamic QR Codes marketers’ favourite.


If the QR Code isn’t working, you should check the validity of ir subscription with your service provider. If needed, you’ll have to renew it.

7. QR Code being Disabled

If your QR Code is not working or has become invalid, then it might be disabled for some reason. This could be because you set an end date for the campaign or a team member disabled it mistakenly.


Regularly check the status of deployed QR Codes. To do it, you can just login to your QR Code generator and check your QR Code’s status. You can also coordinate with your team for the same.

B. How to create QR Codes

Now that you know which scenarios can lead to an invalid QR Code, it’s the time you get started on creating a QR Code. Here are various ways to do that:

I. Create QR Codes one by one

Does your use case not require hundreds and thousands of QR Codes? Then this is the right choice for you. It offers you a wide range of QR Code categories to choose from. For example, Event QR Code, Website URL QR Code, Product QR Code, etc.

To create one, you simply need a QR Code generator. To help you get started, here’s a step-by-step guide on how to create QR Codes.

II. Create QR Codes in bulk

In case, you want to create QR Codes in bulk, you can go ahead with this option.

Here, you’d need a bulk QR Code generation service. It allows you to create up to 100,000 QR Codes in one go. Hence, it eliminates the need to generate QR Codes one by one and saves you a lot of time and effort.

To make use of it, you simply need to upload a data file in XLS, CSV, or XLSX formats. This file needs to have all the data to be encoded in the QR Codes. Once done, you just have to wait for the QR Codes to be generated and download them in a zip folder.

For more information, here is a detailed guide on how to generate QR Codes in bulk.

III. Create QR Codes programmatically

If you want to integrate QR Code generation into your own information system, QR API can help you do it.

With QR API, you can generate QR Codes programmatically in real-time. Hence, there is no manual intervention required to create the QR Codes.

That’s it. These are all the common scenarios that can turn your QR Code invalid. In case you are interested in learning how to use QR Codes like a pro, here’s a detailed guide.

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