QR Code
The number of letters a QR code can store depends on the QR code version, the error correction level, and the encoding mode. The four encoding modes are:
- Numeric Mode: Only digits (0-9)
- Alphanumeric Mode: Letters (A-Z), digits (0-9), and nine special characters (
space,$,%,*,+,-,.,/,:) - Binary Mode: Any byte of data (e.g., ASCII or binary files)
- Kanji Mode: For encoding Kanji characters
Since you are interested in letters, the Alphanumeric Mode is the most relevant for storing typical letters and numbers.
Maximum number of characters a QR code can store in Alphanumeric Mode, based on the version and error correction level:
| Version | Low (L) | Medium (M) | Quartile (Q) | High (H) |
|---|---|---|---|---|
| 1 | 25 | 20 | 16 | 10 |
| 2 | 47 | 38 | 29 | 20 |
| 3 | 77 | 61 | 47 | 35 |
| 4 | 114 | 90 | 67 | 50 |
| 5 | 154 | 122 | 87 | 64 |
| 10 | 429 | 339 | 242 | 181 |
| 20 | 1,208 | 958 | 684 | 511 |
| 30 | 2,034 | 1,613 | 1,152 | 860 |
| 40 | 4,296 | 3,391 | 2,471 | 1,850 |
Key notes:
- Low (L): 7% of the QR code can be damaged and still be readable.
- Medium (M): 15% can be damaged.
- Quartile (Q): 25% can be damaged.
- High (H): 30% can be damaged.
So, for version 40 at the lowest error correction level (L), you can store up to 4,296 alphanumeric characters (letters, numbers, and some symbols).