How big should a QR code be on a poster?

About a tenth of the viewing distance. A metre away needs 10cm; three metres needs 30cm, which is most of an A3 sheet. Size from where people actually stand, not from how it looks on a screen.

How high should a poster QR code be placed?

Between waist and eye height. Codes near the top of a poster mounted high get photographed from below at an angle, and anything above about two metres is out of reach for a person of average height.

Do I need to label the QR code?

Yes. "Scan for tickets" converts substantially better than a bare square, because an unlabelled code asks people to point a camera at an unknown destination. The label costs one line of type.

Where should an event poster code point?

Straight at that event, with date, venue, price and a buy button. A homepage makes people search for the event they just saw advertised, which loses most of the value of the scan.

Why do window posters scan badly?

Reflections off the glass wash out part of the code for much of the day, and the person scanning is outside in bright daylight. Use matte stock, size up, and check it at the times of day people actually walk past.

QR code for an event poster

A poster has a few seconds to convert somebody walking past into somebody holding a ticket. A code is the shortest path between those two states, provided it is big enough to use from where they are standing.

Posters get this wrong more than any other format, because the design is made on a screen where everything is legible and printed at a size where the code is a postage stamp on a wall.

Size from the viewing distance

A code needs roughly a tenth of its reading distance in width. A poster in a corridor read from a metre needs 10cm. One across a café read from three metres needs 30cm, which is most of an A3 sheet and usually means rethinking the layout.

Be honest about where people stand. A poster behind a counter, above head height or in a window read from the pavement is much further away than the designer imagined, and the code has to be sized for the real distance rather than the hoped-for one.

Put it where a phone can reach

Codes belong between roughly waist and eye height. A code at the top of a poster mounted high is photographed from below at an angle, and anything above about two metres cannot be scanned by a person of average height without a step.

In a window, remember the glass. Reflections wash out a code for much of the day, and the scanner is standing outside in daylight — the worst lighting condition for a screen-lit camera to resolve fine detail.

Say what it does

Label it: "Scan for tickets", "Scan for the programme", "Scan to add to your calendar". An unlabelled code asks somebody to point a camera at an unknown destination, and most people simply will not.

Labelled codes convert substantially better, and the label costs a line of type that the poster can almost always afford.

What should be behind it

The single next action, not a homepage. If the poster is about one event, the code goes to that event: date, venue, price, a buy button. Making somebody find the event again on a busy site loses most of the value of the scan.

Use a dynamic code so a sold-out show can be repointed to the waiting list or the next date rather than leaving hundreds of posters pointing at a dead page.

Print and material

Matte, dark on light, high contrast. Gloss under gallery or shop lighting produces hotspots that blank part of the grid, and a hotspot across a finder pattern stops the code working entirely.

For outdoor posters, use UV-stable ink and check them through the run. A code that faded in three weeks of sun is still advertising your event and quietly sending nobody anywhere.

Common questions

How big should a QR code be on a poster?: About a tenth of the viewing distance. A metre away needs 10cm; three metres needs 30cm, which is most of an A3 sheet. Size from where people actually stand, not from how it looks on a screen.
How high should a poster QR code be placed?: Between waist and eye height. Codes near the top of a poster mounted high get photographed from below at an angle, and anything above about two metres is out of reach for a person of average height.
Do I need to label the QR code?: Yes. "Scan for tickets" converts substantially better than a bare square, because an unlabelled code asks people to point a camera at an unknown destination. The label costs one line of type.
Where should an event poster code point?: Straight at that event, with date, venue, price and a buy button. A homepage makes people search for the event they just saw advertised, which loses most of the value of the scan.
Why do window posters scan badly?: Reflections off the glass wash out part of the code for much of the day, and the person scanning is outside in bright daylight. Use matte stock, size up, and check it at the times of day people actually walk past.