Try: · ·

https://ftbl.fr

Characters

15

QR version

1

Modules

21 × 21

Jumbotron range 5 m

~50 m

✓ Readable up to row 35 at the Stade de France.

Understanding QR versions

Why Version 1 changes everything.

The ISO/IEC 18004 standard defines 40 QR code versions, from 1 (least dense) to 40 (densest). Each version maps to a grid of modules (black/white squares): 21×21 for Version 1, 177×177 for Version 40.

At equal print size, the lower the version, the bigger each module, and the further away the QR can be read. The rule of thumb: one module should measure about 1 mm per metre of expected scan distance.

In practice, if you print a 30 cm QR on an urban billboard:

  • Version 1 (21×21): ~14 mm modules → ~14 m range
  • Version 3 (29×29): ~10 mm modules → ~10 m range
  • Version 5 (37×37): ~8 mm modules → ~8 m range

Version 1 only accepts a 17-character URL in strict alphanumeric mode, or ~25 characters in binary mode (standard URL with https://). FTBL.fr fits. Most marketing URLs do not.

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