Choosing the right content type
Picking the right type matters more than it sounds, because it decides what the phone does after the scan.
| You want to… | Use |
|---|---|
| Open a website or a menu | Link |
| Let guests join Wi-Fi | Wi-Fi |
| Save your details to contacts | Contact card (vCard) or MeCard |
| Start a chat | |
| Show a plain message | Text |
| Get paid | IBAN or Crypto |
| Add an event to a calendar | Event |
Size: how big does it need to be?
The rule of thumb used across the industry is scanning distance divided by ten. Read at 30 cm, the code should be about 3 cm across.
| Where it is used | Scan distance | Minimum code size |
|---|---|---|
| Business card | 20–30 cm | 2–3 cm |
| Table card, menu | 40–50 cm | 4–5 cm |
| Product packaging | 20–40 cm | 2–4 cm |
| Poster | 1–2 m | 10–20 cm |
| Shop window | 2–3 m | 20–30 cm |
| Billboard | 10 m+ | 1 m+ |
Two adjustments to that rule: go bigger if the code is dense (a high version number), and go bigger if it will be read in poor light.
The pre-print checklist
- Scan it with two different phones — one iPhone, one Android. Cameras and decoders differ
- Scan the printed piece, not the screen — ink spread closes gaps between modules; a code that works on screen can fail on paper
- Check the destination — one wrong character in a URL and the whole run is wasted
- Keep the quiet zone — clear space around the code, at least four modules wide. Do not let a border or text touch it
- Dark on light — inverted codes work on most modern phones and fail on some older scanners
- Vector for print — SVG or PDF, never a stretched PNG
- Avoid glossy lamination under direct light — reflections defeat the camera
- Add a call to action — "Scan for the menu" raises scan rates far more than any design change
Why codes fail, in order of frequency
- Too small for the distance — by far the most common cause
- Not enough contrast — pale colours on a pale background, or a colour photo behind the code
- Quiet zone eaten by a border — the reader cannot find the edge
- Too much data — a dense pattern that cheap cameras cannot resolve
- A logo that is too large — beyond the error correction budget
- Printed from a low-resolution PNG — blurred module edges
- Inverted colours — light modules on dark, which some scanners refuse
The tool prevents most of these outright: settings that produce an unreadable pattern are not offered, and the ones that carry risk trigger a warning under the preview.
How to create a QR code, step by step
- Choose the content typeLink, Wi-Fi, contact card — whichever matches what should happen after the scan.
- Enter the detailsFill in the fields. The code builds itself as you type, so there is no button to press.
- Adjust the designColour, module shape, eye style, logo and frame. Keep contrast high.
- Test itScan from the screen with at least two different phones and confirm it opens the right thing.
- Download in the right formatPNG for screens, SVG or PDF for anything going to print.
Frequently asked questions
How big should a QR code be?
Divide the scanning distance by ten. Read at 50 cm, make it about 5 cm across. Go larger for dense codes and poor lighting.
Which format should I use for printing?
SVG or PDF. Both are vector and stay sharp at any size. A PNG enlarged for a poster shows soft module edges, which is exactly what a scanner struggles with.
Can I use colour?
Yes, as long as contrast stays high — aim for at least 4.5:1 between the modules and the background. Dark modules on a light background is safest.
Why does my code not scan?
In order of likelihood: it is too small for the distance, the contrast is too low, the quiet zone is blocked, or there is too much data in it. Work down that list.
Do I need to test every code?
Every code that goes to print, yes, on at least two different phones. It costs a minute and saves a reprint.