Make a QR code that never expires

Static codes, and why they do not expire

A QR code is a pattern that spells out data. In a static code that data is your link, network or contact card itself. A phone reads it and acts on it directly, so there is no server in between that could be switched off, count your scans or ask for a renewal fee. That is what every code made on this page is.

Many generators sell "dynamic" codes instead. Those hold a short link on the seller’s own server, which forwards each scan to your page. When a trial or plan ends, the forwarding stops: the help pages of one large generator say its dynamic codes are then deactivated and point to a service page, while static codes keep working. If you print a dynamic code, its life depends on that account.

The one thing a static code cannot do is change after printing. If you expect the destination to move, point the code at a page on your own website and change that page instead. Our guide Do QR codes expire? covers the trade-offs in detail.

How much fits in a QR code

A QR code grows in steps called versions, from version 1 at 21 x 21 modules to version 40 at 177 x 177. More data or stronger error correction means a higher version with smaller modules at the same print size. These are the most bytes each version holds, which is the number that matters for links and ordinary text:

Digits alone fit about 2.4 times as many characters, and capital letters with digits about 1.5 times. DENSO WAVE, which invented the QR code, notes that phones read about 271 bytes comfortably (version 10, level L), so keep codes for phones well below the larger versions.

Choosing an error correction level

Error correction adds spare data so a reader can rebuild what is missing when part of the code is dirty, torn or covered. Each level trades capacity for that safety. DENSO WAVE says level M is the most common choice, and suggests Q or H where codes get dirty.

• L, about 7% recoverable: the smallest code. Good on screens and clean, indoor prints.
• M, about 15%: our default. A good balance for posters, menus and packaging.
• Q, about 25%: for outdoor signs, labels that get handled, or codes that may be scuffed.
• H, about 30%: needed when a logo covers the middle, and chosen for you when you add one.

Size, quiet zone and contrast for print

Leave a clear margin of 4 modules on every side; DENSO WAVE calls this the quiet zone, and scanners need it to find the code. Our preview includes it by default. Size matters more than resolution: what a phone must see is the module, the smallest square. The stats under the preview show the module size at the print width you pick. Here is what that means for a short link in a version 3 code with its quiet zone:

Use a dark code on a light background with plenty of contrast. Light codes on dark backgrounds are read by many phone cameras but not by every scanner app, so the tool warns you before you download one.