Smallest working QR Code

I’ve been playing a bit with QR code generators, and tried to generated a very small one for this homepage. This is the result:

The file is 21×21 pixels, and has just 178 165 bytes. It works with my cellphone from a distance of about 7cm, and gets you to http://martin.ankerl.com/.

How did I create it?

  • Create very short URL to the link you want to create the QR code for. I’ve used j.mp with the customize link feature, and played a bit with special characters like _ until I got a working link.
  • Create a QR code for this link, with low error code correction. This generator has this option.
  • Open the file with your favourite image editor, cut off the border, resize it by factor 1/4 with resample to get a QR code where each black dot is one pixel wide.
  • Save as .png, without any additional information.
  • use IrfanView’s PNGOUT, and afterwards optipng -o9 to recompress the picture.

Can you make a smaller QR code with working weblink?

Have fun!

5 Comments on "Smallest working QR Code"

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Jeff Gonzales
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Hi,

Do you know of any barcode SDKs for the iPhone/iOS that can read barcodes this small?

Thanks,
Jeff

Wesley Wallace
Guest

Working? No. However, I did find a smaller one, inside of a computer’s hard drive. Because it was put there by the company, SOMETHING has to be able to read it:comment image

Malcom Miles
Guest
Yes you can, in this page http://keremerkan.net/qr-code-and-2d-code-generator/ you can create a qr code version called micro qr, wich is a fraction of the size. I’m currently trying to code my web adress into one of those, but the resulting code is 17x17pixels, which is one 1pixel bigger than available space for a favicon. I’m trying to get around this. But a defaul microqr with a shortened code is already 4 pixels smaller than yours in both axis :p Downside is that Microqr could be not so compatible with qr scanners, is not so widely implemented, but is a standard anyway… Read more »
Peter
Guest

If you want to try out yourself and check the smallest readable QR Code with your Smartphone, download the following pdf and print it out: http://qrd.by/download/smallest-qr-code.pdf

On http://blog.qrd.by/2014/07/15/minimum-size-qr-code you will see at the end a list of devices and their scanning capabilities.

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