QR

Why won't my QR code scan?

Usually size or contrast. As a rule of thumb a QR code needs to be about a tenth of the distance it will be scanned from — a code read from two metres away wants to be roughly 20 cm across. The other common causes are a missing quiet zone (codes need clear margin around them), inverted colours (a light pattern on a dark background breaks many scanners), and cramming so much data in that the pattern becomes too dense to resolve.

Why more data makes a code harder to scan

Every extra character adds modules — the small squares that make up the pattern. A long URL with tracking parameters produces a visibly busier code than a short link to the same page, and a busier code has to be printed larger or scanned closer to work at all.

Shortening the destination URL is the single most effective fix for a code that scans unreliably.

Do QR codes expire?

A static code never expires — the data lives in the pattern itself, with no server involved. What expires is the destination: if the page it points to dies, the code leads nowhere.

Codes advertised as expiring are dynamic ones, which encode a short redirect URL owned by a service. Convenient, but if that service shuts down or starts charging, every code you printed stops working. For anything printed on physical material, a static code pointing at a page you control is the safer choice.

Are QR codes safe to scan?

The code itself cannot do anything — it is just text. The risk is what the text points to, and you cannot see that before scanning. Fake codes stuck over genuine ones on parking meters and restaurant tables are a common scam.

iOS shows the URL before opening it. Read it. If a code on a physical surface looks like a sticker placed over something else, do not scan it.

QR Maker – Code Generator

Our iOS app for exactly this. Runs on your device — no account, no tracking.

See the app →