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3 QR Code Specification

3.1 Error Correction

All QR Code error corrections levels will be supported as listed below.

  • Level L (Low) - 7% of data bytes can be restored.
  • Level M (Medium) - 15% of data bytes can be restored.
  • Level Q (Quartile) - 25% of data bytes can be restored.
  • Level H (High) - 30% of data bytes can be restored.

3.2 Versions

QR codes of version 1, 2, 3, 4 will be supported. The following table provides QR Code versions 1 through 4, the number of modules (blocks), and the maximum number of characters that can be represented in the QR Code value for each error correction level.

3.2.1 Size vs. Error Correction

Version

Modules

Max # Characters by Error Correction Level

L1

L2

L3

L4

1

21x21

25

20

16

10

2

25x25

47

38

29

20

3

29x29

77

61

47

35

4

33x33

114

90

67

50

Modules are the number of blocks that are used to create the QR code. For example, Level 1 QR codes contain 25 wide by 25 blocks tall.

Max # of characters define the maximum value that can be stored in a given type of QR code. For example, if the data to be stored on a QR code is 32 bits, the smallest level (least dense) would be level 2.