Using QR Codes: Where They Work, Where They Don't

QR codes entered our lives through menus during the pandemic, and afterwards most businesses didn't know where to put them. Yet their field of use is narrow and clear: the code builds a bridge between a physical surface and digital content. If that bridge isn't needed, the code is unnecessary too.

Do QR codes really work?

When used in the right place, yes. If the user is in front of a printed surface and needs to reach the information there from their phone, a QR code is the fastest route; it creates far less friction than typing an address. A QR code sitting on a screen, on the other hand, is pointless: on a website or in an email there is already a clickable link, and expecting the user to scan a code on the same screen with a second device is a flow that doesn't work.

Where they really work

• Packaging and labels. User manual, warranty registration, ingredient information. Everything that doesn't fit on the box.
• Business cards. A code in vCard format removes the need for the other party to enter the details by hand.
• Shop windows and signs. Even when closed, they give access to opening hours, location and contact details.
• Events and reservations. Tickets, check-in, table booking.
• Invoices and delivery notes. Payment link or shipment tracking.
• Guest WiFi. No need to type the network name and password by hand.

The common point is this: the moment the user sees the code, they have a phone in their hand and a physical object in front of them.

Where they sit in vain

On websites, in email newsletters, in digital presentations and in places where a user on the move can't read them. A QR code placed on a motorway sign is one nobody can scan even if it technically works.

Then there are codes given no reason. A bare square without a note like "scan for the menu" or "warranty registration" next to it arouses indifference in most people, not curiosity.

The difference between static and dynamic codes

In a static code the data is inside the code itself. It has no expiry and always works because it doesn't depend on a server; but its content can't be changed later.

In a dynamic code the code goes to a redirect address, and that address determines the target. You can change the target later and see how many times it was scanned. In return you depend on a service: if that service closes, all your printed codes die.

The practical rule: for jobs that are printed, distributed and can't be collected back (packaging, signs, books), use a redirect address on your own domain so the target can be changed later. That way you get dynamic flexibility without depending on a third party.

Size and contrast rules for print

• Minimum size: don't let the side length go below 2 cm. If it will be read from a distance the rule of thumb is a side length of one tenth of the reading distance.
• Quiet zone: leave a margin of at least one module width on all four sides of the code. This margin is not decoration; the reader needs it to find the code's edge.
• Contrast: dark code on a light background. The reverse (light code on a dark background) doesn't work in many readers.
• Logo: should cover at most a third of the code and must be tested afterwards.
• Background: don't put the code on a photo; a patterned background breaks reading.

Before sending to print, test with at least two different brands of phone, in both good and poor light. There is no fix for a reading problem noticed after printing.

Measuring whether it gets scanned

A static code gives no direct statistics, but you can tell scans apart on the analytics side by adding a campaign parameter to the address the code goes to. Use a separate parameter for each placement: even if the code on the packaging and the one in the window go to the same page, that's how you see which one works.

If you don't measure, you never learn whether the QR code works; most businesses' belief that "QR codes don't work" actually comes from not having measured.

The three most common mistakes

1. Pointing to the home page. The code on the packaging should go to the user manual, the one in the window to contact details. Dropping the user on the home page and forcing them to search makes them give up.
2. Sending to a page that isn't mobile-friendly. Everyone who scans a QR code is on a phone; if the target page looks broken on a phone, all the effort is wasted.
3. Generating the code once and forgetting it. When the target page is removed or its address changes, the printed codes start going to an error page. Scan and check the printed codes once a year.

Working through an example

Say you're putting a QR code on your packaging for the user manual. The things you need to decide are:

• Target: the manual's own page. Not the home page and not a PDF — opening a PDF on a phone is slow and hard to read.
• Address: a short path on your own domain (like yourbrand.com/m/product-name). That way if the manual is updated the same address shows the new content.
• Size: 2-2.5 cm on the box is enough. The user will scan it holding it in their hand.
• Caption: "Scan for the user manual and warranty registration." A code without a caption doesn't get scanned.
• Measurement: add a campaign parameter to the address and see how many people scanned.

Codes printed without these five decisions usually mean thousands of packages going in the bin, because they can't be changed afterwards.

Accessibility and an alternative route

The QR code shouldn't be the only route. Write a short address next to the code too, so a user without a phone, with a camera that doesn't work or who can't scan the code can reach it by typing.

This matters especially with a customer base of higher average age. Placing the code and the short address side by side in printed work gives noticeably more reach than the code alone.

Frequently asked questions

Does a QR code expire? Not a static one; the data is inside the code. A dynamic one depends on the service that generated it; if that service closes, the code stops working.

Can I change a code after generating it? Not a static one. If you want to be able to change it, print the code with a redirect address under your control; you update the target through that address.

Do coloured QR codes work? They work if there is enough contrast. Use a dark colour on a light background; pastel tones and reversed contrast cause problems in many readers.

Which file format should I supply for print? SVG. Being vector, the edges stay sharp on a business card and on a sign alike. PNG is enough only for screen use.

The page the code goes to is part of the job

A QR code's success depends less on the code itself than on the page it leads to. The person scanning is on a phone, standing and usually in a hurry. The target page must be built accordingly:

• What it is should be clear on a single screen; a long introduction isn't read.
• The information sought should be at the top. The manual for a manual code, the menu for a menu code.
• If there's a form, keep the number of fields to a minimum; long forms don't get filled in on a phone.
• The page should be light. The code is usually scanned inside a shop, on a weak signal.

If these four don't hold, there's no result even if the code technically works. If you see a "scanned but left immediately" pattern in measurement, the problem is not the code but the target page.

If you want to generate a free code for a link, text, WiFi or business card and try colour settings, you can use the QR Code Generator tool.