What is the Quiet Zone(Blank Space) Around QR Codes?
When creating a QR code, the importance of the quiet zone (margin) is surprisingly easy to overlook. Failure to secure an adequate margin can lead to reading errors and negatively impact the user experience.
This article explains the role of the margin in QR codes, what happens when the margin is insufficient, and tips for creating proper QR codes. Let's learn the key points to make QR codes that can be read accurately and smoothly!
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What is a QR Code's Quiet Zone?
A QR code requires an empty space of 4 cells outside the black code area. This empty space is called the quiet zone (or margin).
This margin has a clear role and does not exist merely as part of the design. Officially called the "quiet zone," if this area is not properly secured, the QR code may not be read accurately.
This article will explain in detail the importance of this margin and how to set it appropriately. Let's learn the basic knowledge to prevent reading errors and create easy-to-use QR codes for everyone.
The Required Width of a QR Code's Quiet Zone
The required width for a QR code's margin (quiet zone) is 4 cells. A cell is one of the individual dots of a QR code, and the number of cells is determined for each QR code version.
Please refer here for a list of versions and cells.
Example Calculation for a QR Code Margin:
Let's try to calculate the margin. We will create a QR code with the following conditions:
Text Data:
https://qr-stock.comError Correction Level: M
Required Size including margin: 300px × 300px
For creating QR codes, the online tool QR STOCK is recommended. The result of creating the QR code with QR STOCL was version 2.
How to check the QR code version
.png&w=3840&q=75 "the qrcode for this experiment")
(Image of the created QR code for the experiment)
A version 2 QR code has 25 cells on one side. To check the number of cells for each version, please use the following article: a list of versions and cells.
The total number of cells is 25 cells + (4 cells × 2) = 33 cells. The margin width is 4 cells out of the 33 cells. Therefore, the required margin width was found with the following formula:
300px × (4 ÷ 33) = approx. 36.4px
What Happens if a QR Code Has No Quiet Zone?
When creating a QR code, if the margin is omitted or not sufficiently secured, the following problems will occur:
Increased Reading Errors
Inability to Read Due to Design
Degraded User Experience
Let's explain each one.
1. Increased Reading Errors
A QR code reader uses the margin as a reference point when recognizing the entire code. Without this margin, it cannot correctly recognize the QR code's boundaries, which can cause errors. The importance of the margin is even greater for small QR codes or those with complex background designs.
2. Inability to Read Due to Design
When incorporating a QR code into a design, the margin is sometimes ignored. For example, if the background image or color is too close to the QR code, the code and background will visually interfere, and the reader will be unable to accurately identify the code portion.
3. Degraded User Experience
If a QR code cannot be read, the user will either look for another method or, in the worst case, choose not to use the service. A QR code with an insufficient margin also gives a poor visual impression and is not evaluated as a professional design. The ability to smoothly read a QR code depends on securing the margin. Securing an appropriate margin improves convenience and reliability.
Experiment on the Presence of a QR Code's Quiet Zone
So in real life, how much does the presence of a margin change the readability of a QR code? We will verify this with the following devices and services.
Standard camera on an iPhone XR (quite old at the time of writing)
QR STOCK Image Detection
QR STOCK Camera Reading
Android Quick Settings > "QR Code Scanner"
Google Pixel 7a standard camera
Google Lens
Experiment 1: Ensuring a Sufficient Margin
An example with a sufficient margin around the QR code, as shown below.
Result: Of course, if you provide enough margin, it could be read.
Experiment 2: Using a Small Margin
Next, we created a QR code with a margin smaller than the recommended 4 cells. Will this be difficult to read?
Result: Contrary to expectations, it was successfully read without any problems. The reading was successful without any particular difficulty.
Experiment 3: Using Zero Margin
Next, we tried with zero margin. It is now integrated with the outer frame, so will it be difficult to read?
Result: What! This was also read without any problems. And the reading was smooth.
Experiment 4: Removing the Background
Finally, we even removed the background. We will try with two patterns: a gradient and a solid dark color. We expect a result where it cannot be read, or is at least difficult to read.
Result: Both were read!
Results of the Experiment
Since the iPhone camera read everything, we tried an online service as an addition. Detect QR code from image | QR STOCK
Experiment | iPhone Standard Camera | Image Detection | PC Camera Detection | Android Quick Settings | Pixel Standard Camera | Google Lens |
|---|---|---|---|---|---|---|
Exp 1: Normal | Readable | Readable | Readable | Readable | Readable | Readable |
Exp 2: Narrow Margin | Readable | Readable | Readable | Readable | Readable | Readable |
Exp 3: Zero Margin | Readable | Unreadable | Unreadable | Readable | Readable | Readable |
Exp 4: No Background | Readable | Readable | Readable | Readable | Readable | Readable |
Although the experiment was intended to find the line at which the presence or absence of a margin would make it unreadable, the iPhone unexpectedly read everything. Although securing a margin is recommended, it may be that technology has advanced and is more tolerant regarding margins.
On the other hand, the online QR code detection service confirmed that in the example with zero margin integrated with the background, it could not be read.
Therefore, the final conclusion of this series of experiments is that even if there is no margin, there was no problem with the iPhone, but the results may differ depending on the device.
Other Points of Caution Besides Margins When Creating a QR Code
Besides margins, there are several other points to keep in mind to create accurate and easy-to-use QR codes. Below are some particularly important points.
1. Ensure Contrast
The clearer the black-and-white contrast of a QR code, the more accurately it will be read. If the background color is too close to the code, or if the colors are too light, the reader may misinterpret the information. Especially when incorporating a QR code into a colorful design, be conscious of the contrast between black and white, or dark and light colors.
2. Don't Make the Logo Too Large
It has become common to customize QR codes by inserting a logo in the center. Example: QR codes from major SNS like Instagram or TikTok.
However, if the logo is too large, it will cover the information part of the code, and the error correction function will not be able to cover it, making accurate reading impossible.
Explanation of the error correction function here
The logo size should be kept within about 20% of the entire QR code.
3. Keep the Data Amount Appropriate
A QR code has a maximum data capacity for its version and error correction level. As you increase the data, the version becomes larger. If the version is too large, the code becomes complicated, and reading errors increase.
List of QR code versions and storable data capacity
Try to store the minimum necessary data. If the URL is too long, it is necessary to devise ways such as using a shortened URL.
Summary: Ensure a Quiet Zone for Your QR Code
The margin of a QR code is called the quiet zone and is not just a design element, but an indispensable part for achieving accurate reading. By securing an appropriate margin, you can prevent reading errors and improve the user experience.
When creating a QR code, keep the following points in mind:
Secure a margin if possible.
Be conscious of the black-and-white contrast.
Adhere to appropriate logo sizes and information amounts.
The results of our independent experiments showed that even if the margin rules were not followed, they could be read on an iPhone. However, considering the differences in various reading devices and environments, it is always better to secure a margin. Please try to adjust it in balance with your design!
