QR (Quick Response) codes

A QR or Quick Response code is a two-dimensional barcode. These are often used for adding web links to a printed page. When you scan such a QR bar code using a webcam or mobile phone camera, the QR reader application takes you to a Web site, a YouTube video or some other web content. QR codes are an easy way of sending people to a site without having to type a URL. Below is the QR code for http://www.prepressure.com.

QR code for Prepressure.com
QR code for Prepressure.com

Next to being used for linking to share links, QR codes can contain other types of information:

  • A QR code on a business card can contain an electronic version of the contact information. Scan the code and the reader application adds the contact to your address list.
  • A QR code can contain event information. Scan the code on a poster for a concert and the app automatically adds its name, date, and location to the agenda on your smartphone or PC.
  • A QR code can contain an SMS with a phone number and text. Scan the code and the scanning app lets you automatically participate in some contest to win fabulous prices.
  • A QR code can contain an e-mail message with a subject and message text. That message can be a request for information so that in return you might get a reply email with additional information and attached files.
  • A QR code can contain a geographical location. Scan the code on a poster advertising for a restaurant and its location becomes available to your navigation software, informing you how to get to that place.
  • A QR code can contain WIFI configuration data. Scan the code and your Android device automatically configures itself to use the wireless access at the hotel.

There are still more ways in which QR codes can be used. The above list only summarizes the main applications. You can see examples of the creative use of quick response codes on this page. Originally this technology was created for tracking parts in manufacturing processes. In the printing industry, there is finishing equipment that uses such 2d bar codes.

Description of Quick Response bar codes

The Japanese corporation Denso-Wave created the QR matrix code in 1994. It is an open standard for which no license fee has to be paid. The physical encoding of QR codes is nowadays in the hands of various standards bodies, including JIS and ISO (e.g. the ISO/IEC 18004:2006 standard). The standard for encoding URLs was established by NTT DoCoMo, the Japanese telecom company.

QR codes contain information in both the horizontal and vertical axis. Compared to ‘regular’ barcodes, this allows for much larger amounts of raw data to be embedded. These can be numeric, alphanumeric or binary data – of which up to 2953 bytes can be stored. Only a part of each QR bar code contains actual data, including error correction information. Below you see the above QR code with the URL data stripped away. As you can see quite a large area of the bar code is used for defining the data format and version as well as for positioning, alignment and timing purposes.

Positioning, alignment,... data in a QR code
Positioning, alignment,… data in a QR code

The more data need to be embedded, the larger the barcode becomes. Below is the QR code for this page. Since the URL is longer than that of the home page, the bar code has also grown. The barcode after it doesn’t contain a URL but the first 5 sentences of this page.

QR barcode pointing to this page
QR barcode pointing to this page
QR barcode with two lines of text in it
QR barcode with five lines of text in it

The smallest square dot or pixel element of a QR code is called a module. Like with other types of bar codes, it is recommended to have an empty area around the graphic, which makes it easier for devices to read the bar code. This quiet area is ideally 4 modules wide.

The minimum dimensions of a QR code depend upon the resolving power of the cameras that are used to scan the code. According to a Kaywa white paper, it is recommended to use a minimum size of 32 × 32 mm or 1.25 × 1.25 inches, excluding a quiet zone, for QR codes that contain a URL. This guarantees that all camera phones on the market can properly read the bar code. Changing the size to a width and height of 26 × 26 mm or roughly 1 square inch still covers 90% of the phones on the market. The latest camera models, which have improved macro capabilities, can however already deal with QR codes that are less than 10 mm (0.4″) wide and high.

The above rule applies to perfectly printed codes that the user has direct access to. Things change when using QR codes on a poster or billboard. The general consensus is that there is a direct relationship between the physical dimensions of a QR code and its scanning distance. That ratio is around 1/10, so if the reader is 50 centimeters removed from the code, the size of the QR code should be at least 5 centimeters. For a billboard viewable from 10 meters, the height of the code should be at least 1 meter.

For good reader accuracy, good contrast between the background and the bar color itself is very important. The bar code should have a dark color on a light background. You cannot go wrong by treating the QR code as line art, using black on white. If the background needs to be in color, make sure that it is a solid color, not a screened tint. Avoid using cyan or magenta but a 100% yellow background should work fine. Very light Pantone colors might also work, as long as the contrast with the bar code is high enough.

How to read a QR code

To read a hard link or physical world hyperlink, a smartphone or computer equipped with a webcam needs to have the correct reader software. It will interpret the scanned image and launch a browser to visit the programmed URL. Do a web search using the keywords “QR reader” and the make of your phone to find such applications.

How to generate or create a QR code

There are a number of stand-alone barcode generators on the market. I don’t have experience with such applications and cannot recommend any software. I have read good things about Barcode Studio from Tec IT, which is available for both OS X and Windows.

There are also web services that can generate a QR code. I used the Kaywa site to create the above examples.


A Microsoft Tag is a 2D barcode whose intended use is similar to that of QR codes. In comparison, Tag barcodes can be much smaller than QR ones because they use different symbol shapes in geometric patterns and multiple colors or tints to embed more information in less space. Microsoft refers to this as a High Capacity Color Barcode (HCCB). A major difference with QR codes is that Microsoft Tags don’t actually store the information. All the barcode contains is a unique ID which the reader application needs to send to Microsoft’s servers. They will then send back all the linked information. This way more information or a wider variety of data can be included. The disadvantages are that the reader application needs to be online and there may also be privacy concerns with this server-based approach. Given their small size and the use of color (which admittedly isn’t mandatory) my guess is that Microsoft Tags are more difficult to print in offset.

Two other alternatives to QR codes are SpyderLynk SnapTag and JagTag.

Some argue that alternative technologies will reduce the usefulness and adoption rate of QR codes. Among the competing technologies are:

  • image recognition tools like Google Goggles. With such an app taking a picture of a box of cereals can take you to the website for that product.
  • embedded NFC chips.

Additional sources of information

QRworld is an interesting blog.

75 thoughts on “QR (Quick Response) codes

  1. Nice and useful info. I like to share about labelkraft. Labelkraft are an Officials Zebra Associated Partner with Our expertise you can be assured that you will get full support when installing and setting up your zebra Printer. For more : https://www.labelkraft.com

  2. Can we keep the comments on topic please? I am sure there are other threads that you can go post in about EVERYTHING else. Thank you for understanding.


  3. Claire,
    To be honest….
    I think if you have a marketing strategy, know how to make the QR Codes or apps you are talking about. I am sure with a simple brochure, face to face meeting explaining how the company could/would benefit from the QR code you might be able to do very well yourself. Please send me an email [email protected] – Let’s talk a little bit. Ok?


  4. Hi there

    I live in Uk and in a rural area wherethey have only just caught on to the web – would love to start a small business around my kids – could I sell QRs and apps as an feasible income do you think – and who would you suggest approach (if you know any) to work as a ‘franchisee orsales agent’ or is it easy enough to do myself?

    Any advice or help is most appreciated x

  5. Neha,
    That is a good question. However in order to answer that can you share what do the current ID cards do or are used for?

  6. Eric,

    I can’t find the link but there is a form of sorts that you would scan then you can send a sms msg. I set something up for a friend of mine for people to rsvp yes or no for their wedding 🙂 . Google.com

  7. I have a question. The documentation says you can text someone or call their phone. DOes this mean I have to direct the url to a php page that will do this? Or is there a better way ? Please advise, I like the tags setup, easy to convince someone to use it , worked 1st try for me .thx.

    Eric Nickus

  8. At #17 GtrNtn88, I think you’re right, unfortunately. I’d really hate to lose either Driskel or Brissett, but I don’t see either of those guys settling in to a backup role. Maybe I’m wrong though, and the offense will find a way to use both of them in different situations it kinda sorta worked for LSU….maybe us too? Wishful thinking, but stranger things have happened.

  9. Good summary of the technical information and I particularly liked the illustration of varying encoding densities in the QR Code.

    Getting the right physical size for the printed QR Code to facilitate high successful scan rates is important and requires a little math. I use the QR Code size calculator at http://www.qrcoded.co.uk/qr-code-size-calculator/ to get a ballpark figure and then test, test and test again. No point printing a code that no one can read.

  10. Our client requested a QR code for their business cards be made but she wants it to include her sales reps photo, meaning she wants the photo to be imported into a device along with the contact info. I have been researching online but have not found anything that supports the idea that a QR code can include a photo. Does anyone know if this can be done and if so, how?

  11. When you have generated a QR image can you use the same image and change the text that is inbedded in to the code rather than having to re-generate a new QR image.

    1. I see you mention that the QR code can hold just under 3 MB of text. I am sure I read something in my apple news feed that mentioned the ability to actually package an entire website, (A single page scroller it must be) in side the QR code so the scanner need not be connected to the internet to review your website. Does any of this ring a bell, have you heard of such an ability? I guess I kind of answer my own question, if it can hold 3MB data, if that data is the coding for a site then it should be possible. Sorry I have no direct link to specific details, I came to your site looking for that very information.

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  13. We just had business cards done for our client with the QR code on the back. it’s a four color process card but we did a white nock out for the black QR code to print on. problem QR code will not read. when i print out the QR code that they supplied it will not read either. Is there anyone i can send this QR code to and have it checked out to see if it’s a good bar code

  14. I will immediately clutch your rss feed as I can’t find your e-mail subscription hyperlink or e-newsletter service. Do you’ve any? Kindly allow me understand so that I may subscribe. Thanks.

  15. QR code is a great invention people made. I’m making mobile apps currently and find it really cool to implement QR codes into them. I’m amazed at QR code coupons Snappii app builder allows to create. They are really helpful for small businesses.

  16. I am looking for the api to allow qr codes to be designed with custom logos now. If anyone is interested in assisting and or learning we could help each other!

  17. I outsourced the job to qrlicious.com. They charged $60 and had it done within 24 hours….. not to bad I thought.

    1. Interesting….
      How did you get the image inside the QR?
      This is all new to me, so I have been googling and reading up as much as possible…

    2. I sent the above query to the guys at QRlicious.com and they solved the problem! They said the Facebook page must have a username and told me how to set that up. This however did change the URL so the original code did not work so FREE OF CHARGE they did a new one that worked. Now everything is working perfectly.

  18. Just wondering your thoughts on the following issue and if you have seen this before and know how to fix it.
    I had a custom QR code made for our company Facebook page. Some people can scan this and go to the correct facebook page but when I scan it (with several iphone apps I have downloaded) It takes me to my personal Facebook page instead. Thanks [IMG]http://i1152.photobucket.com/albums/p482/Was1ak/JohnSandsFacebookPageQRCode.jpg[/IMG]

  19. I have been googling and don’t see anything specific. You could break the poster apart into smaller images, linking each qr to it’s own separate piece or just link to the whole image.

  20. content=If you have a poster that is only images and you segment the images into QR codes and the viewer would be able to scan the codes and reveal the images and the poster in its entirety. Like I said earlier I am not sure if this is even close to being possible or not.

  21. what do you mean by content?
    I don’t think that is possible at the moment and I don’t think it will be for along time to come 😀

  22. Vai,
    I was trying to figure out how to possibly take an entire poster and break it down into QR codes so that when you scanned the poster it would reveal the content on the poster. So that you could move the phone around the poster to see the poster.

    I am not sure if the technology has come to that point.

  23. Is there any way that you could send me a link to an example or an example for me to see. I would like to see how you set it up.


  24. I was wanting to know if is possible to have the QR code contain picture images. If I were to scan the bar code it would bring up a picture instead of a website or information. If so is there anyway to customize what part of a picture or the picture in general.

    1. Matt,
      I have been looking to do the same thing for a client.
      The closest I have gotten was to create a separate folder for QR stuff,place those images they wanted to be seen then have the code link to a particular image.

      My next mission for the QR code is going to be used for wedding rsvp information.

      Hope this helps. If anyone has done/seen anything different please share!

    1. I don’t see why not…. provided the contrast is high enough. I can imagine that you better play it safe with the dimensions of the code and don’t make it too small. It will probably look pretty fancy – I think QR codes with slightly rounded corners ‘fit’ the best with this type of printing.

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  26. Thanks for this. Quick question – has anyone tried printing a QR Code onto a shirt? If so, can you comment on the effectiveness?

    1. We printed Large QR codes on the back of tees for a local
      24 hour news station. The QR code directs you to the
      daily weather forecast. Also works well as tatoos and on a wide variety of specialty advertising. ‘-D

  27. I have a client who wants to put their QR on a coffee mug. Question #1 will the cameras read on a curved surface. #2 the coffee mug is black and the QR will be in yellow. Will the barcode work with this color combination?

  28. I have seen a lot of variations in the use of QR codes lately. Some have been inside of shapes, some have shapes/logos, inside of them and there has been a mix of color. So long as you remember to leave the required space around the QR code, you can get almost as creative as you want. Just keep in mind that slightly older android and windows phones cannot read reversed QR codes. However they are fixing this in newer models, so it won’t be an issue for long.

  29. Am interested in how to use QR codes on a passport photo with name and contact info for our public event ID programs. Would be delighted to be pointed to where I can get such help.

  30. Can you create a QRcode that would be in any other shape other than the square box? I am working on a client project and they are interested in using their company icon (a shamrock) and having the QR code inside of that. I appreciate any feedback. Thank you.

  31. A great use for QR codes: Digital camera takes photo of person; camera places QR code in corner of photo; photo is uploaded to a computer; QR code becomes part of photo and stays with the photo regardless of the format, particularly when the photo is printed for inclusion in a scrap book.

    Now that the photo has a QR code somewhere in it, then many years from now, when someone finds the photo in an old attic trunk, all that is needed to identify the subject of the photo (and the name of the photog-rapher, locations, date, time, and a myriad of other facts – including life story of the subject) is to scan the photo and QR code in a computer or reader — which will link to a website maintained by a company, for a fee. All the data related to the photo would be in a database, for retrieval.

    The idea came to me doing genealogy/family history. Many of the photos left behind by my late parents contain no info, no names, nothing on the back. Wouldn’t it be nice if there were a QR code on the face of the photo which could be scanned by my scanner/computer and automatically bring me to the website maintaining the database of info placed there by the author/photographer?

    If such a service were available today, I would take these unidentified photos in my possession, scan them, generate a digital photo with a QR code placed in a corner, or placed below the photo – which would allow anyone to whom I sent the photo or found it in a stack of heirloom photos to link to a website to find info that I had added, including my relationship to the subject.

    The uses seem to me are endless, and ripe for entrepreneurship. If only I were younger with a lot of seed money!

    1. I am frankly not a big fan of your idea, for two reasons:
      – QR codes are useful but they still tend to be fairly obtrusive. That would be especially true if they are part of an digital photograph.
      – There is already a well established and standardized way of adding the data that you mention to a picture, which is by embedding them in the metadata. My pictures all have my name in them as the photographer. With a GPS module the location where the shot was taken is embedded. The date and time are always there, even with sub 100-euro camera’s. You’re trying to solve a problem that has mostly already been solved. The only issue is that many people choose to ignore EXIF and XMP metadata.

      However, I do appreciate you taking the time to discuss a possible use of QR codes. Thanks!

  32. I have limited space and I need to know the minimum size QR code would be with the necessary boarder / if a white boarder is important. Any help wuld be great. Thanks!

  33. hey…. possible datas that can be embedded in a qr code?… is there any restrictions in type of data ,,, its size… and what are other possible informationz that can can embedded in QR in future… and the works going on in QR code data embedding

  34. I work for a sign company looking to add QR Codes to outdoor signage. How do I know the proportional size based on distance that I need to actually be sure that these are readable?

    1. The size of QR code you need on a sign or billboard will depend on its distance to the viewer’s cameraphone that is scanning it, and the focal length of the cameraphone’s lens. These will both vary, but per the above article you want to try to make the QR code appear at least 32mm x 32mm (for a URL) OR larger to be recognized by most cameraphones. Choose some parameters like distances between 10-50 meters for distance, and 15-55mm focal length, and then calculate the necessary “angle of view” (google on this and you should find details on the calculation) that is needed to make your QR code appear 32mm x 32mm at those distances and focal lengths. This should tell you how large the barcode must be on the sign at the longest distance it needs to be scannable.

  35. Hi Korey,

    We are a publisher looking to add QR codes to our print visitor guides so the advertiser can provide quick additional info to customers. If you have any experience in this field would love to hear from you.

  36. I personnally use QReasy to generate compressed QRcode. I found it thanks to Lynkee QR reader which is IMO the best barcode reader available so far…at least on my BlackBerry 9700.

  37. Currntly doing a preflight on a print file that is 4 color cmyk and 1 spot. Barcode and QR code are present in this print file. I am curious – in printing QR codes, do they have to be 100% black or 100% spot? Can they be a screen,or process color and still scan?

    1. Denise, I have just come across this exact question. The designer supplied the file in a 4-color black (looked like an RGB file converted to CMYK). I asked for the file in 100% black and all heck broke loose, you’d have thought I told him his designs were the worst in the world. Anyway. So far all I’ve seen about printing specifications of a QR code is a high dpi and solid colors. I’d like to find something that says “can print in color, but use 100% of said color”
      Thanks for any help!

  38. They (QRC’s) seem to ease commercials, so i expect info about security or controlsoftware to be kept from inet away/filteredm like cookiemanagers are difficult for find.
    In Japan existing off ’94 and standard app on mobile, it looks easy for users, and devlopment seemed to have slowed down because of costs of hardw.scanners. if i am wrong, tell it.
    Hardly found about sec.

  39. These have just appeared on Facebook profiles. Nobody knows what they are, what they do & if they are a security worry. Can you explain at all? Can people visiting my profile make a code to bypass my securtity on Facebook?

    1. A QR code is in such cases the equivalent of a URL. If visitors can create some kind of URL that bypasses your security, there is no value that a QR code would add to this. I don’t think you need to worry that QR codes have some kind of impact on the security on Facebook. The company Facebook itself is a bigger security risk than a barcode that points to one of the URLs that it hosts.

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