Alignment Pattern
Alignment patterns are small concentric squares (5x5 modules) placed in QR codes Version 2 and above. While finder patterns detect the overall QR code position, alignment patterns correct internal distortion.
When QR codes are scanned at angles or printed on curved surfaces, module positions shift. Alignment patterns serve as reference points to calculate distortion and restore correct module positions. Higher versions have more alignment patterns, handling greater distortion.
In practice, alignment patterns matter most when you create a custom-designed QR code. If a logo or illustration covers an alignment pattern, distortion correction stops working and the code may fail to scan. When customizing a design, keep logos clear of both the finder patterns and the alignment patterns.
How many alignment patterns does a QR code have?
It depends on the version. Version 1 has none, alignment patterns appear from Version 2, and their number increases as the version grows, because larger symbols need more reference points to correct distortion across the entire code.
| Version | Center coordinates n | Alignment patterns |
|---|---|---|
| 1 | - | 0 |
| 2-6 | 2 | 1 |
| 7-13 | 3 | 6 |
| 14-20 | 4 | 13 |
| 21-27 | 5 | 22 |
| 28-34 | 6 | 33 |
| 35-40 | 7 | 46 |
The count follows mechanically from the rule n = floor(version / 7) + 2 center coordinates per axis, giving n² − 3 patterns (the 3 corners overlapping the finder patterns are excluded). The center coordinates are listed in the annex of ISO/IEC 18004: Version 2 uses row/column positions {6, 18}, placing its single alignment pattern at (18, 18); Version 7 uses {6, 22, 38}, yielding 6 patterns after removing the 3 corners.