QR codes for silent auctions

The gap between a guest liking an item and a guest bidding on it is where in-person auctions lose money. Historically it was a clipboard and a pen. Now it is a phone, and the QR code is what connects the two.

They are simple enough to feel like they need no thought, which is how events end up with codes that worked on a laptop and fail under venue lighting.

This page covers the codes themselves — sizing, contrast, placement and why they fail. For the printed sheets they sit on, see display sheets and bid sheets. Part of our full silent auction guide.

What QR codes solve

Three things, at an in-person or hybrid event:

1. Registration friction. A guest who has to type a URL from a poster mostly does not. A scan is a tap.
2. Item-level navigation. Someone standing in front of an item wants to bid on that item, not find it in a list of sixty.
3. Getting bidding onto phones, which is what lets people keep bidding after they walk away from the table — and after they leave the room.

That third one is the real prize. A paper bid sheet stops working the moment the guest moves. A phone keeps working all week. See hybrid auctions.

Auction-level vs item-level

Use both. The auction-level code gets people registered and browsing; the item-level code captures the moment of interest in front of a specific thing. Skipping item-level codes and relying on a single entrance poster is the most common under-use.

32auctions generates item display sheets and printable bid sheets with QR codes, which covers most of what an event needs without designing anything. See display sheets.

Where to put them

• On every item's display card, at the top, where a hand reaching for the item will not cover it.
• On table tents at every dining table, so seated guests can browse during dinner — which is when a surprising share of bidding happens.
• At the entrance, large, with a one-line instruction: "Scan to bid."
• In the printed program, if you have one.
• On the how-to-bid card, which is the highest-value piece of print at a hybrid event.
• On screens, between other content, sized for the back of the room.

Where you should not put them: behind or underneath the item, on a curved surface, at knee height, or anywhere a guest has to move something to scan.

How large to print

The working rule of thumb is that a code's printed width should be about one tenth of the distance it needs to be scanned from.

When in doubt, go larger. An oversized code costs nothing; an undersized one costs you every guest who tries once and gives up.

Leave a clear quiet zone — blank margin — around the code, roughly the width of four of its own modules. Text or graphics pressed against the edge is a common cause of scan failure.

Printing that actually scans

• Matte, not gloss. Glossy stock and laminate reflect room lighting straight back into the camera. This is the single most common cause of a code that works at home and fails at the venue.
• Dark code on a white background. Not brand teal on cream. Contrast is what the camera is looking for.
• Never invert. Light code on dark background fails on many phones.
• No photo behind it. It looks better and it scans worse.
• Print at full resolution. A code scaled up from a small screenshot has soft edges and unreliable scanning.
• Print the plain URL underneath, in readable type. Always. It is the fallback for older phones, damaged codes, and guests who simply prefer typing.

The failure modes

In rough order of how often they ruin an event:

1. Venue wifi. The code scans, the page will not load, and the guest concludes the auction is broken. Test the actual network in the actual room, and tell guests if cellular is better. Do not assume the venue's guest wifi will carry two hundred phones.
2. Glare. Laminated cards under spotlights. Matte stock solves it.
3. Too small. A one-inch code on a poster people read from six feet away.
4. Covered. Placed where the item, a flower arrangement or a guest's hand sits on top of it.
5. Low contrast. Tasteful, on-brand, unscannable.
6. Wrong link. Every item card carrying the same code because the template was duplicated without changing the target. Catastrophic and entirely preventable.
7. No fallback URL. One point of failure with no recovery.

Test before the event

Fifteen minutes, and it prevents nearly all of the above.

1. Print one final card exactly as it will be produced — same stock, same finish, same size. Not a proof on office paper.
2. Scan it with at least three different phones, including an older one and at least one of each operating system.
3. Scan it in the actual room, under the actual lighting, at the actual distance.
4. Confirm the page loads on venue wifi and on cellular.
5. For item-level codes, spot-check that several different cards go to several different items. Do not check one and assume.
6. Confirm the fallback URL is typed correctly and works.

QR mistakes

• Only one code at the entrance. Wastes the item-level moment entirely.
• Glossy or laminated. Looks good, does not scan.
• Designed over a photo. Same problem.
• No printed URL. No recovery when scanning fails.
• Never tested at the venue. Lighting and wifi are venue-specific.
• Same code on every item. Check before you print two hundred cards.