The Quiet Zone

The quiet zone is a part of the QR code. It is defined in the following way in the QR code spec:

“This is a region 4X wide which shall be free of all other markings, surrounding the symbol on all four sides. Its nominal reflectance value shall be equal to that of the light modules.”
The X mentioned above refers to the width of a dark module (which should be same as the width of a bright module), 4X means width of 4 modules.

The quiet zone is an area that should be taken into account when calculating the print size of your QR code on any printed media. According to the spec a version one QR code will take on print twice the area of the QR code itself due to its quiet zone. Technology however may change this. What if all readers work fluently with 2X quiet zone? Area after all is a central factor when it comes to print – do we have to comply to specs when technology allows us to bend them or even ignore them? Is there a new quiet zone rule that we can stick to and if there is what the relevant new quiet zone area is?

First tests with quiet zone

Here are three QR codes the left one has a 4X quiet zone area and the right one has 1X quiet zone and 2X quiet zone in the middle . Below are tests results of various readers on iPhone and Android devices, I assume that the same readers will perform similarly in other platforms like Blackberries Symbian and Windows phones – where they exist.

4X quiet zone                        2X quiet zone            1X quiet zone

As you can see all readers have no problem to scan a 1X quiet zone QR code. So there is no need any more for anything more than 1X quiet zone.

The question is – can we go further? Can we go inside the 1X quiet zone and still get a readable QR code?

Invading the quiet zone

In the left is the same QR code with 1X quiet zone where the quiet zone here is violated once in each direction without destroying original QR code data. In the middle is the same QR code but here the 1X quiet zone is violated around the finder patterns. The right QR code has a quiet zone violation that encircles the finders without violating the quiet zone for the finders themselves.
The last QR code has a high EC to help it recover the corrupted data.
The reader results follow.

When only one reader had a problem to scan the codes in the left and in the right, more than half of them could not read the middle code where the finding patterns quiet zone was violated. It is interesting to see that almost all readers (except one) do not need a fully surrounding 1X quiet zone when the spec requires a 4X surrounding quiet zone.

This means that not only a 1X fully surrounding quiet zone is all what QR code needs today, it means also that this 1X quiet zone must not encircle fully the whole QR code. What is really important is giving the finder patterns a 1X quiet zone and nothing more. Going down from a 4X quiet zone to 1X quiet zone around the finders only is a huge space saving. Use that space to increase your QR code on print or alternatively – your QR code will consume a much smaller printing area!

To make sure that only the finder patterns needs a quiet zone for practically all readers here is an extreme example of QR code where only the finder patterns quiet zone exists.

Checking this code with all the readers above will show the same results we got for the right QR code in previous example. So not only 1X quiet is enough but this 1X quiet zone can be limited only to the finder patterns of the QR code. Not only it saves print area, it also permits new kinds of decorated QR codes.

Posted in create QR codes, designed QR codes, print QR code, QR code quiet zone, QR code size, QR codes, QR codes contrast | Tagged , , , , , | 3 Comments

Decorating a QR Code – Part Two

After dealing in previous post with neutral (non damaging QR code data) decorative means, we are going to look at more aggressive means and learn their possible effect. We will try to estimate their damage amount and ways to control it in order to create decorated QR codes that are still decodable.

Pattern colored QR codes

A more aggressive way (in terms of QR code readability) to color a QR code, is to use a pattern as a color. This effect can be achieved by using the bucket tool and painting the QR code with a pattern instead of a simple color (in Photoshop for example). When painting with a pattern use the Medium EC level and above. Here is an example of such a QR code created in this manner with a grass pattern (created from an image) in Photoshop. The QR code EC level in this example is Medium.

The problem with pattern coloring is the contrast between the elements in the pattern. Readers must in some point decide which module is bright and which module is dark. To simplify this we can imagine a black and white QR code somehow created from the original colored image. The contrast play in pattern elements might create white spots in dark modules in this final decision image of the reader. Here are two possible black and white interpretations that readers may face in trying to decode the image above.

As you can see the main problem is the white stripe in the upper right finder patterns. The following readers were able to read the original colored QR code on an iPhone.
NeoReader, Scanlife,MobileTag,RedLaser,Scanit,Qr scanner, Optiscan, BeeTagg, i-nigma, QuickMark,Qrafter,and Scan.

Only Qr Reader for iPhone failed to read the original code. After correcting the contrast in the upper right finding pattern in the right image below, all readers including QR Reader for iPhone were able to decode the QR code.

Original image                              Corrected image

What can we learn from this? First thing is that most scanners can handle the contrast level in the pattern at the left QR code above. Secondly – look for areas in the pattern that might be too bright in the QR code finder patterns and try to lower the contrast in these areas. The finder patterns are sensitive since readers must find them clearly as a first step in decoding. Third thing is to look at other areas in the QR code, if there is a suspect for too much brightness, consider changing the pattern or lowering the contrast in the original pattern.

Hiding the QR code

Using patterns for coloring QR codes can easily create a QR code which is hard to detect for a human eye but is easily detectable by a machine. Here are some examples – the first from Set-Japan ( a company that created really nice decorated QR codes.

To my surprise this QR code is detected by almost all QR code readers in the market when you are close enough to the image.

Using a pattern that our brain is trained to recognize like bars or circles in a QR code will make the QR code even more difficult to detect. Here are two examples I created using bars and circles.

I used for this example a QR code with high EC but I am afraid I did this only because it looks hard to detect in our human eyes. As it appears it would be totally detectable also in a low EC, since once the background is detected from the foreground the QR code data is fully available here.

So – which readers were able to read these ones? Here is the list
i-nigma, scanlife, RedLaser and ScanIt.
Almost all other readers decoded only the left QR code above. The reason for failing the right one for most readers is not the pattern or the ability to detect the QR code. The same QR code painted with red (instead of yellow) was read successfully by all readers on an iPhone that decoded the green QR code above.

Combining effects on QR codes

The QR code below is a result of applying a ripple distortion on a regular QR code. Although it is much obvious to human than the hidden QR codes above, it is harder for the machine to decode it. Actually the rippled QR code needed the Reed-Solomon error correction since two codewords were corrupted in the rippled QR code, while none of the codewords was corrupted in any of the hidden QR codes above.

Here is a combination of ripple and the green bars

Complicated as it might be seen almost all readers reads this code and the damage made to the data is very small – only 2 codewords were damaged out of 22 possible for a QR code version 3 high EC.

Applying a decorative means that damages X codewords on a QR code over a decorative means that does not hurt the data at all, will usually end by a damage of X codewords as happened above.

However applying a decorative mean that damages X codewords upon one that damages Y codewords will not always end by damaging X+Y. codewords. Here is an example.

Spherical QR code – 2 codewords corrupted

Rippled QR code – only 2 codewords were corrupted.

Spherical and rippled – only 2 codewords corrupted

Posted in color QR codes, designed QR codes, error correction, hidden QR codes, pattern coloring QR codes, QR codes, QR codes contrast, QR codes readers | Tagged , , , , , , , | 4 Comments

Decorating a QR Code – Part One

Decorating a QR code is not a simple task as it may sound. Decorating QR codes has been taken by some artists to a level of an art in itself. Some decorative means will not affect QR code readability, we will call them neutrals. Other decorative means will undoubtedly affect it. Decorating QR codes using neutral means enables you to work with low EC (Error Correction levels) and probably with lowest version of QR code. Using lower QR code versions increase readability, assuming that total QR code area is fixed on the printed media.

Some decorative means will disrupt readability just a little while other might affect readability seriously up to the point of non readability.

What are the neutral ways to decorate your QR code? Which means will hurt readability to small extent and what means should be measured carefully when used? How can we know how much of the readability we are hurting? I will try to answer some of these questions in this post.

Neutral decorative means for QR codes

The simplest non harming way to decorate a QR code is to color it in a different color that the default -black. If this is all what you plan to do and your QR code is not going to live in a harsh environment (see here), use a Low error correction level. Normally coloring the QR code with one color is not going to affect readability at all. You must however to take into consideration the contrast between your color and the white background. For example coloring your QR code with a bright color will surely affect decoding with some readers.

Bad foreground color

The next step in complexity is adding the background into play – changing the default white background to another color. This is more complex because a new factors should be taken into consideration – who is darker the foreground or background?

It is hard to state a rule for the contrast since not all readers achieved the same minimal contrast for decoding. Here are test results observed on an iPhone with some readers. I used for the test a black Low EC QR code on varying backgrounds. The lines with reader names along them are the points where the specific reader was able to read the code in this contrast.

So if your QR code is dark on a brighter background see if one of the three weakest (contrast related) readers reads it. If one of them does, your contrast is ok.

In case your foreground is brighter than the background you should know that not all readers support this (although their number grows with time). This situation of darker background arises whenever a darker color is used for background. Here is an example:

This is a list of readers that supports the inverted option:
I-nigma, Neoreader, MobileTag, Qrafter, Lynkee, Scan

More disruptive decoration

The next decorative steps may make decoding a little more hard. The first step is rounding the QR code finding patterns. Doing this should not affect readability for small versions and very slightly for big QR code versions. Here is an example for a QR code with rounded finding patterns.

The QR code error correction level should not change for this kind of decoration since the effect on readability is very minor if at all. The way to achieve this effect in Photoshop is selecting the fQR code finding patterns and then using the select/modify/smooth filter with a small value. This will modify the selected finding patterns to be round as in the image above. Create a new layer and paint the selected area with your foreground color. As a last step remove the finding patterns from the layer below the topmost layer to get the desired effect.

Using more than one color for the QR code creates a good visual effect. A common way to do it is to color the inside of the finding patterns with a different color as in the image below. If the new color is in good contrast there should be no effect at all on the code readability although minor damage might sometimes occur by greater rounding of the corners.

t has been recommended in few places to use only black and white colors due to readers compatibility. I have tested all iPhone QR code readers that I know of and all of them had no problem to read the multicolor QR code above except the MobileTag reader (which by the way decoded smoothly the all blue rounded QR code).

Rounding all QR code modules will hurt readability more. Here is an example –

The main impact is on the isolated one module boxes which changed shape. Their area is now smaller. This might affect QR code readability since scanner usually sample the environment of the module to decide its color (dark/bright). When rounding the QR code elements take into account the size of one module in pixels. In general do not smooth with more than half of module width in pixels, since this would affect the isolated dark modules too bad. In the example above around half of permitted errors occurred in reading this QR code (Low EC)– leaving only 3.5% percent secure zone. It is recommended to go up to a Medium error correction (15%) level whenever rounding all QR code modules. The rounding itself should not harm more than 5% of data area – leaving more than 10% for secure zone which should suffice for most QR codes.

Adding shadows with or without embossing is further step that still (as above) should not affect more than 5% of data area. Here is an example

The reason is that some of the isolated one module boxes that lost area gets now some support from the close shadow. So some errors might now be corrected while some other white modules might be calculated now wrong because of the same shadow. Here again the Medium EC (or more) is recommended for this type of decoration.

Coloring some of the modules with an additional color as in the image below should not change matters dramatically as long as the other color is dark as the first foreground. Here the color is brighter which may cause a difficulty for some readers although most readers will handle multi colored codes reasonably. In case the color is too bright the impact can be calculated by counting the isolated colored modules.

n our example there are 23 orange modules (the orange module inside the guiding pattern is not part of the data and should not be counted). If they were all white the code would be unreadable because only 4 codewords can be corrupted in a QR code version two with Low EC (see table below). Remember that a codeword is 8 connected modules in two connected columns of 4 rows each(see here for detailed explanation). Since the orange modules (in this example) are spread in more than 4 clusters (and hence more than 4 codewords) the Low error correction level is not enough here, and the QR code would not decode if they were too bright.

Here is a table that shows how many code words can be corrupted for each EC level of the first four QR codes versions.

Posted in color QR codes, designed QR codes, error correction, QR codes, QR codes contrast, QR codes readers | Tagged , , , , , | 3 Comments

QR Codes Scanning Distance

The invisible bubble of space that constitutes each person territory plays a major role in our social life. In his book “The Hidden Dimension” Edward T. Hall elaborates on the distance factor role in animal social life and humans as well. It appears that people use the same distance rules when interacting with objects as well and QR codes are not an exception.
Many times people mention that they were embarrassed to scan a QR code in certain circumstances, or needed to act strangely in order to scan a code. See and for such examples, both by the way are excellent examples on how not to use QR codes.

This is when the hidden distance factor enters into the play, a factor that we must be well aware of it if we want a good response for our QR codes.

Meaningful distances for humans

Four distances are mentioned in Hall book;
– The intimate distance – effectively zero distance
– The personal distance – this is the distance separating members in a no-contact state. It might be considered as the protecting sphere that individuals maintain between their self and others. The length of the arm plays a major role in defining this distance and it ranges between 1.5-2.5 feet (1/2 to 3/4 meters)
– The social distance – this is the distance that people feel comfortable with, in a social gathering. It allows a normal voice communication and it goes between 4-12 feet (1.25-3.6 meters)
– The public distance – this is the distance considered to be well outside any social involvement. This distance goes between 12 feet and above (more than 3.6 meters)

QR codes are encountered in different circumstances, many of them fits into one of these distances.

QR codes for intimate distance contacts are QR codes on objects that are considered to be yours, or are good candidates to be. Sometimes you are at your own when interacting with them and sometimes not. Few examples
-QR codes inside a magazine or newspaper
-QR codes on envelopes mailed to you
-QR codes on business cards ( you can even interact with them from close distance in public)
-QR codes on the menu in a restaurant
-QR codes on supermarket objects
– QR codes on books/DVD covers

These QR codes are expected to be interacted with from a small distance; it can be as small as the camera focus on your device can go.

QR codes that fit into the personal distance are QR codes that are in your arm distance after extending your arm towards them. Examples-
-QR codes on high shelves objects in supermarkets
-QR codes on electrical products in a shop
-QR codes on bus stations
-QR codes in a zoo or museum

QR codes that are expected to be interacted within a social distance are QR codes positioned in places where many people are gathered. Examples-
-Subway wagons
– Inside buses
– Underground stations
– Inside clubs or pubs
– In halls of movie theaters

The last category is QR codes in the public zone. These QR codes go usually on outdoors big signs, in entrance to malls or street advertisement. The most natural way to contact them is from a distance of 12 feet and above. Examples-
– QR codes on T-shirts
– QR codes on sign posts or buildings

Every distance has an equivalent QR code size. For the intimate distance the rule is easily derived from the camera capabilities on mobile devices today. The rule that holds for almost all current devices is that each module of the QR code must be at least 0.028 inch tall, in print.
That means that a QR code version one (21×21) modules must be at least 0.58 inch tall to be able to be read from a very close distance. Note that a version 2 QR code (25×25) must be at least 0.7 inch tall to reach the same effect.

For all other distances where focus is not an issue – the question is – how tall should the QR code be in print in order to be read from the expected distance?

Distance and QR code size

Fortunately the question is not hard to solve, elementary school math provides all we need to get the answer.

The view angle of camera devices today is between 45-53 degrees (in a 90 degree for a right angle system). Let’s take the 45 degree example, from the fact that tan(45) = 1 we conclude that the height of what we see on the mobile screen is equal to our distance from the object we are aiming to.

So if we are in distance of 3.2 feet we are going to see on our 320 pixels height mobile screen an area height of 3.2 feet. Assuming that every QR code module of a decodable code must be at least a 2 pixels height (which holds for most readers), we get that a version one QR code (21×21 modules) must be at least 42 pixels tall on the screen. 42 pixels out of 320 pixels are 0.13 of screen height. All screen height is represent a 3.2 feet height in reality (in our example) – hence our QR code must be in reality 0.13*3.2 = 0.42 feet or 5.4 inch (12.8 cm).

So for scanning distance of say – 1.5 feet, we need for a version one QR code 2.4 inch height (6 cm). The following table contains the size of QR code in print for the various distances mentioned above.

Scanning distance QR Version1 print size QR Version2 print size QR Version3 print size QR Version4 print size
Personal – 1.5-2.5 feet (45-75 cm) 2.4 – 4 “
(6-10 cm)
(7.15-12 cm)
3.3 – 5.5″
(8.2 – 14 cm)
3.7 – 6.3 “
(9.5 – 15.8 cm)
Social – 4-12 feet (1.2-3.6 meters) 6.3 – 19″
(16-48 cm)
7.5 – 22.6″
(19 – 57 cm)
8.7 – 26.2″
 (22 – 66 cm)
9.9 – 30 “
(25 – 75 cm)
Public 12-25 feet (3.6-7.6 meters) 19 – 39 “
(48 – 100 cm)
22.6 – 46.5″
 (57 – 120 cm)
26.2 – 53.8″
 (66 – 166 cm)
30 – 61.3 “
(75 – 157 cm)

These sizes are calculated assuming the camera view angle is 45 degrees. In case the view angle is a little bigger add until 15% to these sizes (up to 53 degrees). In general the smaller the view angle the closer the object will appear on the screen. Zoom lens use a very small view angle which takes a small portion of what we see and put it in the entire screen – which causes the zoom effect.

Also note that everything here is linear so if you plan for another distance – use same ratio as in the table to get your QR code size in print.

The other side of the story

All this can be looked at from a different angle. Assume you already printed a QR code in height of X inches and look at his scanning radius. The smaller the versions of the QR code the greater its scanning radius. The following illustration shows the ratio of the scanning radius for different QR code versions, when the QR code height in print is constant.

Let’s look at the area that the scanning radius provides. If a version one QR code at height X covers a Y area, a version two QR code at same height will cover only 70% of area Y while version 4 will cover only 40% of area Y.

This is why using the smaller QR code version for an outdoor ad is so critical. You are losing 60% of your potential audience if you put a QR code of version 4 instead of a version one QR code, while both take exactly the same printing area.

So use capital letters for URL, URL shorteners, low error correction if you do not intend to decorate your QR code.Minimize the version as you can. Life however is not always in black and white and a high version decorated QR code may attract more clicks than a non decorated lower version one.

Posted in print QR code, QR code business card, QR code scanning distance, QR code size, QR codes | Tagged , , , , , | Leave a comment

Owning a QR Code

One of the fundamental requirements for any capitalist economy is the right for property and the ability to protect this right. Thomas Hobbes noted in 17th century “My own can only truly be mine if there is one unambiguously strongest power in the realm, and that power treats it as mine, protecting its status as such.”

I would like to consider in this post the subject of owning a QR code- can a QR code be a private property? If the answer is yes, who then is the highest power protecting this right?

QR codes are not physical entities. If I own a table it is mine, even if you own an exact copy of my table – my table remains my property and your table remains yours. The fact that two physical objects look the same is not relevant to the property issue. Actually a central power of modern economy hides in its capability to mass produce objects that looks the same.

However all of QR code functionality hides in its look. Add to this that they can be produced for free (and hence duplicated). Is there any sense than by questioning whether a QR code can be owned? Can it be a private property?

For being able to answer this I looked after the rights that come from owning a property. Here they are:

1 – The right to control the use of the property
2 – The right to benefit from the property
3 – The right to sell it or give it to somebody else
4 – The right to prevent others from using it

Since the only effective way of using a QR code is by scanning it, there is no problem with 1 and 2 above. The big problem here is rule number 4 – how can I prevent others from using it? Right number 3 – selling it, cannot hold if any of the other rights is violated. So if we only can find a way to prevent other from using it (when the owner wants to) – may it be that we are at the dawn of a new economy era?

Before trying to answer this challenge I would like to make a quick review on the two first rights mentioned above.

Controlling your QR code

Some companies will sell you the ability to control your QR code. The type of control they provide is modifying at your own will the QR code target. To reach this affect the QR code does not contains the target URL but an intermediary one. This one will use a script or a table that will redirect the browser to the final target. You the owner have the ability (by login to a site with an account and password) to change the target URL at your wish.

Thinking of it – this is a powerful feature gained by relatively simple means. Take for example buying a QR code for your dog collar. Whenever your QR dog collar is inspected it will show a message that this QR code was created by so and so – advertising the QR code producer. Whenever you feel that your dog is lost – you can switch the QR code to point to your phone number, address, suggested price for the return of the dog – whatever. Moreover the QR code provider might also inform you that your QR code was clicked from such and such location right now. I find it quite impressing – the ability to remote control a piece of paper on your dog collar, or even more impressing many pieces of paper around the world with a single click.

Benefits from your QR code

One of the common benefits from QR codes (beside the effects you gain from clicking on them) is the ability to access their clicks traffic data. Google analytics will provide you this service for free under two conditions:

1- You are the owner of the URL encoded in the QR code
2- You need to plant a small piece of code into your HTML.

This is actually a tracking done on the website and you can get this data as the owner of the site – without any connection to the issue who is the QR code owner.

Other companies will give you a QR code with an intermediary URL (like in previous example) while the in-between URL will collect the click data before sending it to the target URL. This will provide you with your QR code traffic data without being the owner of the URL. provides you this service for free if you create the QR code on their site.

While the two last examples collects traffic data only when they reach the site, QR code readers can provide more. They can tell you how many clicks were done that did not reach the site as well. They can also pick for you more detailed location information and other interesting pieces of data – but that may be a subject of another post.


Controlling who can use your QR code

 I am sure that many of you ask – why would I like to prevent other from reading my QR code? Isn’t the secret wish of every QR code owner that everybody will scan his code?

Well there are of course situations when you do not want anybody else being able to activate your QR code. For the sake of example alone I provide the following situation.

Imagine that your door lock is controlled by a wireless mechanism and that you own a QR code containing a URL that whenever reached will open the lock for few seconds. So you will not need any keys anymore you simply click the QR code on your door and the door opens.
The important point here is that only you can scan this QR code. It is open for everyone and everyone can try to scan it – but you and only you as the owner is able to activate it!
Your QR code ownership provided you the control on a physical object (your door lock). That makes the ownership on a QR code something worthwhile.

 I must stress here that this is not a good idea. Somebody can tear the QR code from your door or drawing on it with black ink or even simply stick another QR code on the door and robs by that the control you had on your door. Sticking a false QR code over yours is especially malicious because it can lead to providing the ability to enter your home to others, in case you scanned the false QR code, trying to open your door.

Before giving a good example of this private scanning capability, I would like to explain how this private scanning magic is possible.
For this you need cooperation from your QR code reader. Your QR code reader will be the entity that will sell you these private codes, but not the only one. You must have for this effect something that will identify you as a different entity than anybody else; you will need a unique user id.

This user id may be an arbitrary sequence of digits and characters that does not identify you personally in any way. Actually even the reader itself may have no idea who you are. You may be totally unaware of this id, you may know about it but not knowing what is it, but whenever you scan a code your user id will go with the http packet to the target URL.
 Most URL’s will have no idea what to do with it and will ignore it.  The URL that unlocks doors will check the QR code content, will match it with your user id and in you go.

Note that using a different reader will require another pair of reader-user id to be registered with your QR code in the unlocking locks service site. As the owner of the QR code you will be of course granted with the ability to add other family members to the controlling group as well as other devices in case you own a few and other readers that will support the user id feature as well.
I am reminding again that this is a bad idea – do not use it. Here is a better one.


A private QR code example

Put a private QR code on the inside of your front car windshield. Use it for starting and stopping your parking. This is a totally private QR code, only you can pay for it and more important only you can stop the parking. Combine this with geo location and your parking fees automatically adjust to the locality.

Once you control the content of the QR code you can decide what other will see when clicked. For example other people may see details on your car in case you would like to sell it; you may enable them through the QR code to ping you in case you know you may be blocking somebody, or counting on a good soul that may want to warn you on a nearby parking inspector.

Parking inspectors will be able to get your parking status and you will be also able to get an indication whenever an inspector checked your parking.

Let’s say that your local municipality issued this QR code for you. It can define several users groups; each will see one of the many faces of your QR code. Parking inspectors will get your parking status; Fire compartments will be able to call you upon clicking the same code and you will be able to choose what other will see when they click it as well as starting and stopping your parking.

One question remains – how all these groups id are assigned for all these different people?

Surprisingly or not it can be done – using QR codes.
Let’s say that the municipality created your QR code. The first person that will click your parking QR code should be you – and as such you will be registered (with your user id) as the owner of the code – the one that starts and stop the parking, and control who else may do this.

For assigning special group ids another special authorizing QR code should be introduced to every worker in this group. This special QR code scanned by the QR code reader will assign the group id encoded in the QR code to the scanning device.

From now on whenever the QR reader application detects a parking QR code, it will check for one of possible group ids on the device and send this group id to the QR code target URL, together of course with the regular user id – that’s to enable the parking inspectors pay for their own parking too 🙂

A last word regarding QR code readers – do not forget that QR code reader SDK are available today in the market and every municipality/company can easily create its own parking application that will support all these features. It is important to know that everything mentioned here- is possible.

Posted in Control QR code, create QR codes, Parking QR code, pets and QR codes, Private QR code, QR code ownership, Qr code usage, QR codes, QR codes potential, Tracking QR codes | Tagged , , , , , | Leave a comment

QR codes for Real Estate

If you have any connection to real estate marketing, you probably can’t miss the new hype surrounding QR codes. Their appearance is growing on real estate printed material, on real estate signs and even on realtor’s websites. Many of these codes will direct you to mobile sites and some of these sites are really helpful and effective. Not all QR codes are presented correctly and there are many examples of wrong and good execution of the codes.
QR codes are an excellent tool for real estate – use them! They will filter out customers that search for something else, freeing your time for the more serious customers. They will bring you new customers that you may have never reached otherwise. They will even save you time since some things may be done now remotely thanks to QR codes.
Here are some guidelines that will help you to use QR code correctly and effectively for real estate marketing.

To split or not to split

A question that often rises is, should I have one QR code for my assets or should I use a set of different QR codes? My answer here is clear – use many, as many QR codes as needed. Do not be afraid to create many different QR codes because their specific context is important. QR codes signs are also are recyclable, so creating them is just a onetime effort.

Create location sensitive QR code. A location sensitive QR code is a QR code that can tell you where it is located. The simplest way to do this is not by asking the customer to turn on the GPS for getting his/her location in the moment of scanning, since not all users will allow this. The best way to do this is to add a parameter to the URL decoded in your QR code. Simply encode to signify your system that QR code number 12378 was clicked. Once decoded you know at your site where exactly the QR code was clicked. Now decide what the relevant action is and provide the relevant information. We will see examples for this shortly.

QR code size

QR code size is very important for outdoors sings and I am going to explain why. The bigger your QR code is the greater its decodable radius is. Think of it, by multiplying your QR code size by 2 you are increasing your target audience by 4. Increase the QR size by 1.4 wills double the number of customers that reaches you from these QR codes. Since we do not have here a focusing problem – all camera devices focus quite well for distances greater than 2 inch – there is a simple rule connecting the QR code size to its scanning distance. Every QR code module height should be at least 0.23 inch (6 mm) so that a person will be able to read it from a distance of 3.25 feet (1 meter). A QR code module is one black or white dot in it. This ratio is the same for greater distances (0.46 inch for 6.5 feet – etc). Version one QR codes have 21 modules. Add to these 2 additional modules in each side for quite zone and you have 25 modules. If you want people reading your code from a distance of 6.5 feet your QR code should be 11.5 inches tall (9.6 inch without the quiet zone), 23 inches will reach people at distance of 13 feet. Version 2 QR codes requires 25+4 modules for quite zone, they should be 26.8 inches tall to reach people at distance of 13 feet. So it is important to have a low QR code version as possible. Here are few guide lines for choosing your right QR code.

1 – Do not use low error correction level for outdoors signs. Use a Medium error correction level for your QR code as a starting point. See here a list of QR code generators that create Medium EC level QR codes.
2 – Add a parameter to your URL address to identify the specific QR code that was scanned.
3 – Try capital letters for regular websites, they will create better QR codes (with smaller versions and bigger modules) for you.
4 – If your URL is too long try a shortened URL (do not change it to capital letters here).
5 – Try going up in EC level for your QR code, if version does not grow choose the higher EC level QR code. It will provide you a better readability from far distance as long as your QR code version does not grow when you go up in EC.

Here is an example of a QR code found in

Here are two other QR codes with lower versions and same URL.

The A QR code has a Medium EC (15%) version 4, while the B QR code has a Quality EC (25%) version 4 too. The original QR code has a higher EC (30%) but is of a higher version too – version 5.
In that case always prefer the B code over the A code, since it will be more readable under dirt glare and other hazards that might happen, and it does not take more size.
The  QR code is reachable from a distance greater by one tenth from the distance enabled by the original QR code, its area coverage is 20% more than the original one. You have of course to choose whether the additional 5% in EC is more important than extending the reading distance. Since the QR code is not decorated and its data is not harmed at starting point I will go for the Quality 25% with greater distance. By the way the mobile site behind the code is well executed and can be served as an example on how to make a good mobile site for real estate. I am sure there are other good mobile sites there as well.

Where to apply QR codes for Real Estate

1. Business cards. Put a QR code on your business card. In case of a real estate it is not a bad idea to put two QR codes on your business card, one with your contact details and one with a URL pointing to a mobile site with all your current and updated property listing. Make sure that the QR code with your details can be saved easily to the contact book on your client phone. For general instructions and tips on creating QR codes for business cards – see my previous post

2. Property flyers. Provide a QR code with a URL pointing to your updated offers. If you advertise specific houses put a QR code that leads to special content related to this house. It can be a video showing the interior and environment of the house, it can be a detailed description with photos and the best is a mobile website with a range of options including your contact details and a way to book them into the phone.

3. Billboards & Other Outdoor Environment. Here the size of the QR code is important as mentioned above. Try to put it in an average human being height– not too low or too high. Decorate it and make clear – where it will lead you. Provide location/context relevant information, for example if the QR code is on a bus station, provide your customer with a map showing houses connected to the bus route. Provide a map that shows the properties for sale around the spot the QR code is located in.

4. Real estate signs. These are usually located near houses for rent or sale. Create a special QR code for this property (if it has a sign it deserves a QR code as well). Provide relevant information for the property, people do not scan such codes to get general info on your agency. Show a video; take your customer to a virtual tour in the house. Photos of the property inside and additional details like open house hours will also interest your customer. Provide also a link to other properties similar to this one and other properties in this neighborhood.

5. Brokerage or agency office windows. This is a place where it is reasonable to put a URL to your general mobile site. If your office is high like second floor or above, think of the size of the QR code, see the QR code size title above. For general explanation on QR code versions and EC see my previous post

6. Websites. Do not put QR codes in your website that leads to other pages in your site, or to your mobile site, regular links are made just for this and desktop sites still looks better on computer screens. If you want to put a QR code on your website, put a QR code with your contact details so that your customer can easily book you in his mobile phone.

A do it right checklist

1. First and very important point – target all your URL QR codes to mobile sites. Regular websites looks awful on phone screens, by missing this point you will create a bad image in the customer’s eye and you will lose the opportunity to provide your potential customer with relevant information and making him/her to contact you.

2. Video – although it is not wise to provide a video for outdoors scenes, the situation of a customer standing in front of a house he considers to buy is an exception. Not all phones support the same video format, if you provide a video you must be aware of the type of phone you are going to send the video to.

Note – every time a phone reaches your website its identity is contained in the http-header, you can search for iPhone, Android, Nokia or any other device type, and direct the correct video format as answer to the http request. This is not a difficult thing to do and it is much better than presenting the user with buttons to choose his phone type for getting the correct video – as some mobile sites do.

3. Provide some text or graphics telling the user where the QR code will take him, add a suggestion where to download a reader – not all devices have one.

4. Quiet zone – assure that there is a quite zone around the QR code on the sign. Here is a bad example I found in Google images. Don’t do that; leave a space of at least two modules width around the QR code. Although good readers will be able to read this – do not count that your potential customer is using one.

Although the QR code worked well and the property was sold – it still suffers from a missing quiet zone. Not all readers will survive this. It contains no hint to where the QR code will take you and has no suggestions on where to find a reader.

5. Take scanning distance into consideration. Design your QR codes so that their size and location will enable reasonable scanning distance.

6. Find a service that will track your QR codes. This is especially helpful if you have QR codes that you can identify by parameters as described above. If you one of your QR codes is located in a place that provides a great number of clicks, put behind its link in the mobile site a varying or attractive content.

7. Add a link to Facebook or Twitter in your mobile site, so that people can consult their friends. Social media proves to have a major impact on buying decision of people today. Your Facebook page is also an option.

8. Last but definitely not least – test your printed code in real final size. Use at least two readers – just to make sure there are no surprises.

Finally, use the flexibility that identified QR codes provides you. When the property is sold you can remotely change the URL page content to a ‘sold property’ page without reaching the physical sign. You can suggest in this page to your disappointed customer other similar assets in this neighborhood. The same sign with same QR code can be later positioned near another property.

Posted in create QR codes, error correction, QR code business card, QR code generators, QR code real estate, QR code scanning distance, QR code size, Qr code usage, QR codes potential | Tagged , , , , , , , | 3 Comments

How to Create QR Codes for Business Cards

Creating a QR code for a business card may sound like a challenge. Truth is that everybody can create a QR code for a business card and the steps are quite simple. It is important though to understand the constraint of the task. You do not have much space on your business card because you will probably want to leave the text there as well. On the other hand the QR code that contains all your details may be quite big. Shrinking it to a small printing size might turn it to be not decodable. However following the steps below turns this challenge to be a quite simple task. 

Creating a QR code for your Business card

If you want to put a QR code on a business card you have two options; one is to encode a URL to a landing page where all details are, including a link for saving contact to phone books. The other option is to encode all your details in a vcard or MEcard format so that they can be saved into contact books directly. Here is an example of same data decoded in a vcard and MEcard formats. Both QR codes are in Low EC (Error correction) which is perfect for business cards. Going into a higher EC will make your QR code grow, not a good idea when you are so limited in size.

As you can see the MEcard format is much more compact. The version of the vcard created QR code is 9 (53×53 modules), where the MEcard version is 5 (37×37 modules). Readers will be much more comfortable with the MEcard format – the QR code modules are bigger in size which makes it easier for readers.

Whenever a QR code is printed it is important to make sure it has a quiet zone around it. Look at the white ring around both QR codes in the image below, this is the quiet zone. It should be at least at a two modules width. The QR code spec requires four modules but all readers work perfectly with two as well.


Size considerations

The width a QR code module (black or white dot) should not be below 0.027 inch (or 0.7 mm); otherwise some readers might not be able to read it. Using this minimum size the MEcard will be printed on an area of 1.02 inch (2.6 cm), while the vcard QR code will be 1.43 inch (or 3.6 mm) which may be too big to be printed on the front side of a business card, it can however go to the back side.

How do I know what version is my code? A simple way to detect the version is to count how many black modules are in the timeline. Every QR code has two timelines one is horizontal and the other one is vertical. The time lines are on the bottom line connecting the horizontal finding patterns and on the rightmost bars connecting the vertical finding patterns. The time lines are identical in content so counting one of them is enough.


Here we have 11 dark modules on the timeline (colored red). To get the version subtract 1 and divide by two, (11-1)/2 = 5 here the version is 5. To get the number of modules for a version – multiply the version by 4 and add 17. Here 5*4 +17 = 37 modules width.

Check that the total width of your printed QR code divided by number of modules is no less than 0.027 inch. If this is ok your QR code will be decoded by common readers. Why is this? The 0.027 inch per module is a size that will focus with almost all common cameras on smart phones today. The 7% spare that the Low EC provide should be enough for every reader to overcome the impurities of image capturing – assuming that you do not draw on your QR code.


Where to create the code

Here is a group of QR code generators that creates all their QR codes in Low EC – which is exactly what you need for business cards

MEcard generators:
1. Zxing project –

vcard generators:
1. GoQRme –
2. BeeTagg –

This group lets you choose the EC (choose Low) and supports both vcard and MEcard formats.
1. Azon Media –
2. Kerem Erkan –
3. Good-survey – in advanced settings

I do not mention here other QR code generator that creates by default codes in higher EC level, since the QR codes versions tends to be bigger, which is not good for our case here.


Final touch

Is decorating the code an option? Yes it is – but do not draw on the QR code. You can color it; just make sure that the color has enough contrast with the background.

When size is so small for every module I will be careful when rounding corners or adding other effects.

If you use a URL to a landing page (and if you shorten it) you will probably have a small version of QR code, which means big modules in print. In that case you can try to create a QR code with a Medium or even Quality EC level and add effects or even draw a small logo on the QR code -do not exaggerate though, size is still an issue.

Make sure that your QR code has a quite zone of at least 2 modules around it. That means that text should not reach the envelope of the QR code. This might cause some readers problems in reading your QR code.

See if you can print your QR code image in a vector format. Vector formats enables a smooth shrinking of QR code size on print, without compromising on image quality. Popular vector formats are – SVG, PDF, VML and EPS. Some QR code generators enables saving the QR code image in one of these formats. If you prefer working with jpg or png formats check that the final printed barcode does not suffer from too blurred borders.

Test your printed code (in real final size) with one or two readers – just to make sure there are no surprises. No need to test with more readers, if you followed these simple rules most readers will read your code without problem.


Readers support

Not all readers support the adding to contact books feature.

Also note that on the iPhone some readers will not support the add to phonebook link in your landing page, in case you chose to put a QR code with a URL pointing to a site with your details.

Here is a list of readers that will add your vcard or MEcard QR code into contact books on the iPhone:
MobileTag, Scanlife, Red laser, I-nigma, Optiscan, BeeTagg, QuickMark, QR After, Lynkee and Tap reader

The following supports only the MEcard format
ScanIt and QR Redaer for iPhone

On Android devices – QuickMark supports only the MEcard format while QR Droid, Barcode scanner, Beetag, i-nigma, Red laser, Lynkee and scanlife supports both formats.

So it looks like readers support more the MEcard format, which makes it the preferable choice for direct booking on a business card.

By the way in case I forgot some popular reader or a vcard/MEcard QR code generator, please let me know, I will gladly add it – it may help to make the process even easier.

Posted in create QR codes, error correction, MEcard 2D code, print QR code, QR code business card, QR code generators, Qr code usage, vcard 2D code | Tagged , , , , , , | 4 Comments