# Data capacity

> Data capacity is how much a QR code can hold, and it depends on three things at once: the version, the error-correction level and the encoding mode. The maximum is 7,089 digits, 4,296 alphanumeric characters or 2,953 bytes.

Source: https://useqr.app/glossary/data-capacity · Last reviewed 2026-08-21 · UseQR is free forever, MIT licensed, no signup.

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## The absolute maxima (version 40, level L)

| Mode | Maximum |
|---|---|
| Numeric | 7,089 digits |
| Alphanumeric | 4,296 characters |
| Byte (UTF-8) | 2,953 bytes |
| Kanji | 1,817 characters |

At level H those figures drop to 3,057 / 1,852 / 1,273 / 784.

## The practical ceiling is much lower

A version-40 code is 177 modules across. To be scannable by a phone at arm's length, each
module wants roughly 0.5 mm, giving a 9 cm square. Most real applications should stay under
about 300 bytes.

## The cheapest capacity win

Switch modes. Uppercase alphanumeric costs 5.5 bits per character; byte mode costs 8. A URL
written `HTTPS://EXAMPLE.COM/SALE` encodes about 45% more efficiently than the lowercase
equivalent — free capacity for no design change. Paths remain case-sensitive on most
servers, so only uppercase the scheme and host.