A business card with a QR code: how to make one that stays valid

What a QR code on a business card actually does, the two ways to make one, and the mistakes that leave it unreadable, or dead after six months.

What a QR code does, and what it does not

A QR code is just text, usually a web address, drawn so a camera can read it. There is nothing else inside. When someone scans it, their phone reads that text and offers to open it. Everything that matters therefore happens after the scan, on the page the code points to.

That is the first thing to understand before printing one: a flawless code that leads to an empty page, or to a page that no longer exists, is worth nothing. The code is the door. What matters is the room behind it.

Two ways to do it, and why one is better

The code holds your details directly. You can write a contact file (a vCard, see what that is) into the code itself. Real advantage: it works with no signal. Drawbacks: the code becomes dense, so hard to scan at small sizes, and above all it is frozen. New number or new role means reprinting. No photo, no updates, no link to your booking page.

The code holds a link to a page of your own. The code stays simple (a short address scans at two centimetres) and the page can change. It carries your photo, your links, and an "Add to contacts" button that hands over an up-to-date contact file at the moment it is asked for. Last year's paper cards stay correct.

We built Vizy around the second way, because the first is a paper card with extra steps.

Make one in five minutes

1. Create the page. With Vizy: an account, your name, your details, a photo, and publish. The address looks like vizy.me/your-name, and it is free.
2. Download the code. From your member area, as SVG for print (it stays sharp at any size) or PNG for screens.
3. Place it. On the back of the paper card, in an e-mail signature, on your phone's lock screen, on a stand at the counter, on the last slide of a talk.
4. Test it. With two different phones, one of them not yours, before ordering five hundred cards.

The mistakes that cost

• Too small. Below two centimetres a side, the result depends on the camera and the light. Two and a half is comfortable.
• Low contrast. Light grey on white, or white over a photo, reads badly. Dark on light, with an empty margin around it (readers need one).
• A link that dies. Many "free" generators route the link through their own domain and cut it when the trial ends. The code must point at an address you control.
• Stretched. A code pulled wide to fill a space no longer reads. A QR code is square.
• No context. A black square on its own does not say what it does. One word next to it is enough: "My details".

And after the scan

What the person sees in the second after scanning decides everything. A page that loads fast on mobile data, a name, a face, a button to save. No form, no app to install, no banner to dismiss.

If the page asks for an account first, or takes four seconds to appear in a station concourse, the paper card would have done better. That is the only test we set ourselves for Vizy: what happens after the scan has to be simpler than typing a number.