Turn a link, a Wi-Fi password, or a short message into a scannable QR code in seconds. Learn what QR codes can hold, how to style them, and how to test them before printing.
By Ernzi Tools team · November 6, 2026
QR codes are the fastest way to move someone from the physical world to a digital one: point a phone camera at a code on a poster, a menu, or a business card, and a link opens instantly. No typing, no spelling mistakes. Creating one takes less than a minute, and you can put almost anything inside — a website address, a Wi-Fi password, a short text, or contact details.
The most common use is a URL: a link to your website, a product page, or a video. But QR codes can also store plain text, an email address with a prefilled subject, a phone number, or Wi-Fi credentials so guests can join your network without typing a password. The limit is about 3,000 characters, but in practice shorter is better — the more data a code holds, the denser and harder to scan it becomes. If your link is very long, shorten it first, then generate the code.
A QR code must be big enough for a phone to read from a realistic distance. As a rule of thumb, the code should be at least 2 cm (about 0.8 inches) wide for close scanning, and roughly 1 cm of width for every 10 cm of scanning distance — so a poster meant to be scanned from a meter away needs a code around 10 cm wide. Contrast matters just as much: dark modules on a light background scan best. Fancy colors and logos in the middle look good, but they can break scanning, so always test a styled code on several phones before printing a batch.
A static QR code contains the destination directly — the link is baked in forever, and if the page moves, the code breaks. A dynamic code points to a redirect service, so you can change the destination later without reprinting. For anything printed in bulk — menus, flyers, packaging — a dynamic code is worth it. For a one-off link that will not change, a free static code is all you need.
Placement decides whether a code gets scanned at all. Put it where people naturally pause and have their phones out: on a restaurant table, at a checkout counter, on the back of a business card, or at the bottom of a poster. Avoid curved surfaces, glossy reflections, and spots where the code will be folded or scuffed. Leave a quiet margin of white space around the code — at least four modules wide — so phone cameras can find its edges. And add a short line of text next to it saying what it does, such as "Scan to see the menu" — a code with no context is easy to ignore.
Links are the most common QR payload, but far from the only one. A Wi-Fi QR code lets guests join your network by pointing their camera at it — no password typing, no spelling mistakes, and you can change the password later by printing a new code. A vCard QR code puts your contact details straight into someone's phone book when they scan your business card. Cafes and shops use payment QR codes so customers can pay without touching a terminal. Event organizers put codes on tickets that open a map to the venue, and museums place them next to exhibits to open audio guides. The pattern is always the same: the code removes one small moment of friction — typing, searching, asking — and that small saving is why people actually scan it.
QR codes feel like magic the first time you use them, but they are just a convenient container for text. Generate one, test it, and put it where your audience can actually scan it — at eye level, well lit, and big enough to notice.
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