SMS QR code — 720px PNG

Worked example

Make a SMS QR as a 720 px PNG for print up to about A6: enter the number and the draft text, then scan the download.

A salon's counter card saying "text BOOK to reserve" works best with a short, unique keyword rather than a sentence, because the draft arrives pre-filled and the customer only presses send. Remember that carriers may charge for the message, and say so if the number is not a local one.

The SMS code is about 29 × 29 modules at level H, so after the default 18 px margin 684 of the 720 px hold the pattern and one module is about 23.6 px. Printed at 300 dpi the SMS code is 61 mm wide (2.00 mm modules), fits an A6 card of 105 × 148 mm and reads from about 61 cm.

Common mistake with a 720 px SMS code: trusting the PNG's built-in border as the quiet zone. On the SMS code the default 18 px margin is only 0.8 modules, while scanners want about 4 (94 px). The slider stops at 48 px (2.0 modules), so leave a blank border of at least 8.0 mm around the printed SMS code in your layout, and keep contrast at 4.5:1 or better, since the tool refuses to export below that.

The SMS code has only 29 modules, so at 720 px the default level H (about 30% recovery) usually tolerates the centred logo at 22% width.

Check the 720 px SMS file before using it: scan the download with two different phones, and for a print do it from about 61 cm, ten times its 61 mm width. At 720 px the result should be this: the messages app opens a draft to +12025550123 with 'Hello' typed in, unsent.

+12025550123
Hello

PNG · 720 × 720 px

SMSTO:+12025550123:Hello

A 720 px SMS PNG prints 61 mm wide at 300 dpi, so judge it at that size before sending it to print.