QR code is a bar code that can encode the text, URL, or any data. QR means “Quick Response” because it responds at a very high speed when scanned by a QR barcode scanner.

QR is an application of two-dimensional symbology encoded with black modules against a white background that can be read by special scanners to produce binary data from an image that the phone camera captures when pointed towards these codes. Scanning QR codes enables you to send SMS messages, add people to your contact list, open URLs, and many more actions depending on the information encoded in these codes. For this whole process to work, both devices involved need to have support for decoding/encoding QR codes in their operating systems.

QR barcode scanner

Having a QR code scanner on your phone can come in handy in many different situations. For example, you could have one in your doctor’s office to quickly look up information about certain health conditions or medications in an instant without having to spend time looking it up for yourself. They are also very commonly used in Japan, where they are printed all over the place so people can easily access information using their phones’ QR scanners. Similarly, it might be useful if you’re shopping online and want to compare prices between several websites.

QR barcode scanner

All the major operating systems (iOS, Android) allow users to install QR code readers from App Stores. This means that basically, anyone with any type of smartphone has the ability to decode QR codes.

QR barcode scanner

Just about every QR code contains four different types of information: the version, what it contains, its size, and an error correction level. The version states which standard of QR code is being used. Version 1 was the original, while version 2 offers many more capabilities, including containing URLs. All iOS devices decode both versions without any problem. But some new Android phones only do version 1 because they are designed for Japanese markets where that is the standard.

QR barcode scanner

You can tell what type of data a QR code holds just by looking at its contents bitmap mode. If you want to know more about how these work, check out this tutorial on all things QR code.

QR barcode scanner

The size of a QR code is determined by how much data it contains, but not the way you might think. The number of modules in the x-axis should equal the number of bytes, while the y-axis should equal the number of bytes plus one. This is because each pair consists of an even number of bits, so when you divide by two to get the byte count for this axis, you have to add one to get back to an integer value.

QR barcode scanner

Every QR Code has an error correction level that falls between 1 through 10. A higher error correction means that more redundant information is encoded into the QR code itself, allowing it to be read even if it has several damaged or missing modules.

QR barcode scanner

With a QR code scanner, you can scan QR codes practically anywhere and learn more about what they contain without needing to type anything in on your mobile device. With the recent advent of mobile payment systems like Google Wallet, this will become increasingly useful as users can quickly access their credit cards by scanning a QR code.

You just need to download a QR Code Scanner from an application store that is compatible with your phone’s operating system, then hold up your phone camera so that it points towards the code.