The short answer
QR Island doesn’t sell tickets or check them at the door, and neither does any plain QR code generator. A ticket needs two things a printed code can’t provide on its own: a different code for every ticket, and a scanner that checks each one against a list and lets it in only once. A ticketing service or a check-in app gives you both.
A generator is still useful around the tickets: the code on the poster that leads to the ticket page, the venue map, the programme on the night. Those are further down.
How a ticket QR code works
When someone buys a ticket, the ticketing system creates a record for it and gives it an identifier, usually a long random string nobody could guess. The QR code on the ticket often holds only that identifier. The buyer’s name, the seat and the price stay in the system.
At the door, staff scan the ticket with the organiser’s check-in app. The app looks the identifier up and asks three questions: is it a real ticket, is it for this event, and has it been used? If it’s valid, the app marks it used and shows a green screen. Scan the same ticket again, or a screenshot of it, and the app says it has already been checked in, and when.
That check is what makes it a ticket. The code itself is easy to copy; the system simply refuses the second copy. Some refinements you’ll come across:
- Offline check-in. Many check-in apps download the ticket list before the doors open, so scanning works without signal, and sync later. With several entrances, the devices have to sync with each other, or a copied ticket could get in once at each door.
- Codes that change. Some ticket apps show a code that refreshes every few seconds, so a screenshot passed to a friend is already out of date.
- Signed codes. Some systems put the ticket details in the code with a digital signature, so a scanner can spot a forged code without a connection. It still needs a list to catch a genuine code used twice.
What a static QR code can’t do
A code from a generator is a picture of some text. Everyone who gets a copy has the same thing, so it has hard limits as a ticket:
- It can’t tell guests apart. If every guest gets the same code, it identifies nobody.
- It can’t be used only once. Nothing records the scan. A screenshot, a photocopy or a photo of someone else’s ticket scans exactly like the real one.
- It can’t be cancelled. Once it’s sent, it works for ever, refunded or not.
- It can’t take payment. It can link to a payment page, but the code has no idea whether anyone paid.
You could make one code per guest with a number inside, but then someone at the door has to look up each number and cross it off, which is the job a check-in app already does. A dynamic code doesn’t solve it either: it counts scans of the code as a whole, not per person, and it can’t refuse a second scan.
Options for a small event
- A free event with known guests: an RSVP form, and a printed guest list at the door, ticked off by name. For 50 people that is quicker than scanning, and no codes are needed.
- Paid tickets: a ticketing service handles payment, refunds, a unique code for every ticket, emailed tickets and a check-in app. Most charge a fee per paid ticket, and several don’t charge for free events. Compare who pays the fee (you or the buyer), how soon the money reaches you, and whether the check-in app works offline.
- Tickets on the door: a card reader, and a stamp or wristband for people who step out and come back.
Where a plain QR code helps
Static codes are good at sending people somewhere, and around an event that covers a lot:
- The poster or flyer, to the ticket page. Better still, link to a page on your own site that links to the tickets. When the event sells out, that page can say so and point to a waiting list or next year’s date, and the printed posters keep working. A poster read from 1–2 metres needs a code 10–20 cm wide; a flyer held in the hand, about 3 cm.
- The venue and the way in. A location code for the entrance you want people to use, or a link to a page with parking, the step-free entrance and the nearest bus stop.
- The programme. Set times, the running order and the bar menu on a web page you can update on the night when a set runs late. A page reads better on a phone than a PDF.
- Wi‑Fi for performers and crew, on a separate guest network, and afterwards a code to a feedback form or a shared photo album.
Venues are often poor for signal: basements, old halls, fields full of phones. Keep the pages you link to light, test them on mobile data at the venue, and remember that a ticket page needs a connection to sell anything.
Make it in QR Island
The QR Island studio makes the codes around the event, free: Link for the poster and the programme page, Location for the entrance, Wi‑Fi for the crew network and Event for a save-the-date that adds itself to calendars. They’re static, so they never expire, and they’re made in your browser. Use your ticketing service’s own codes for the tickets.
Press Get QR code for the flat code, then download it as PNG or SVG, or open the print sheet to check sizes. Our print size guide covers posters read from across a room.
