Barcodes for Event Tickets: QR, Aztec and PDF417
See which barcode formats power concert, movie, and sports tickets, why Aztec and PDF417 are common, and how gate scanners read them in under a second.
Buy a ticket to a concert, a movie, or a train ride today and you'll almost certainly get a barcode instead of a paper stub. But not every ticket uses the same barcode. Look closely and you'll see square QR codes, dense Aztec patterns, or wide rectangular PDF417 codes depending on the vendor. Each format was chosen for a reason tied to how fast it scans, how much data it holds, and how hard it is to counterfeit.
What Barcode Format Do Most Event Tickets Use?
Event tickets mostly use QR code, Aztec code, or PDF417, and the choice usually comes down to the ticketing vendor rather than the venue. QR code dominates general admission and email tickets because every smartphone camera reads it without an app. Aztec and PDF417 show up more often in high-volume or fraud-sensitive ticketing like transit passes and major concert promoters.
QR codes are the default for small and mid-size events run through platforms like Eventbrite, because organizers can generate them for free and attendees can screenshot or print them without friction. The format holds up to a few thousand characters, more than enough for an order number, event ID, and seat assignment, and its square shape with built-in finder patterns makes it easy for any camera-based scanner to lock onto quickly.
Aztec code is the standard chosen by the International Union of Railways for e-tickets, including Deutsche Bahn's mobile tickets, under a specification called UIC 918.3, according to Scandit. It is also one of the four symbologies IATA permits for electronic boarding passes under the BCBP standard, alongside PDF417, Data Matrix, and QR code, per Wikipedia's boarding pass entry. Aztec was built without a quiet zone (the blank margin most barcodes need), which lets it pack onto a small phone screen and still scan reliably.
PDF417 shows up on tickets that need to carry more structured data per code or that come from vendors who built their systems around it early. It's a stacked linear format rather than a grid, so it looks like a wide rectangle of short bars rather than a square of dots.
Why Do Some Tickets Use Aztec Instead of QR Code?
Aztec code is chosen over QR when a ticketing system needs a smaller code with no quiet zone and strong error correction for low-quality phone screens. It holds less raw data than a QR code at the same size, but it is denser and reads well even when partly obscured or displayed on an older, dimmer phone display.
According to Scandit, Aztec's structure means it "does not require a quiet zone," the blank border most 2D codes need around them, which makes it easier to fit onto crowded ticket layouts and phone lock screens without wasted white space. It also uses Reed-Solomon error correction, the same family of error correction used in QR codes, so a scratched screen protector or a glare spot usually doesn't stop a scan. That resilience is part of why rail operators across Europe standardized on it for mobile tickets rather than switching to QR.
Why Do Some Ticketing Platforms Use Rotating Barcodes?
Rotating barcodes exist to stop a single ticket image from being screenshotted, printed, and resold or shared to multiple people. Instead of a static code, the app displays a code that changes periodically and is tied to the buyer's logged-in account, so only the device showing the current, valid code can get someone through the gate.
Ticketmaster's SafeTix is the best-documented example. Ticketmaster's own support pages describe it as a barcode that "automatically refreshes," tying the active code to a verified fan account so that "screenshots, screen recordings, and counterfeit tickets" don't work at entry, per Ticketmaster's SafeTix page. When a ticket is transferred to someone else, a new barcode is issued and linked to the recipient's account rather than simply copying the old code. Independent testing has found the underlying code format to be PDF417, refreshing on an interval that Ticketmaster's own pages describe inconsistently as every few seconds to every few minutes, which suggests the exact timing may vary by implementation or has changed over time.
The tradeoff is real: rotating codes cut down resale fraud and screenshot sharing, but they also mean a dead phone battery or no signal at the door can leave you stuck outside, since the current code typically needs a live connection to the ticketing app to refresh.
How Are Ticket Barcodes Scanned at the Gate?
Gate scanning works by reading the code with a handheld scanner or a scanning app, then checking that identifier against the ticketing platform's live database before letting someone through. The whole round trip, from scan to a green "valid" or red "already used" screen, typically takes under a second when the venue has a stable connection.
Most large venues use dedicated 2D imager scanners or tablets running the ticketing company's own scanning app, connected over the venue's Wi-Fi or a cellular hotspot. Each scan sends the ticket's unique ID to a server, which flags it as redeemed so the same code can't be scanned twice, a basic but effective defense against someone showing up with a copy of an already-used ticket. For a closer look at how general-purpose scanning works on a phone without special hardware, see our guide on scanning barcodes from your phone.
How Do I Generate a Barcode for My Own Event?
For a small event, you can generate a unique QR code per attendee using a free online tool, encoding an order number, name, or ticket ID that you track in a spreadsheet, then check off manually or with a basic scanning app at the door. This works fine for community events, fundraisers, or small meetups where fraud risk is low.
For anything larger, where duplicate or forwarded tickets are a real concern, it's worth using a dedicated ticketing platform instead of generating static codes yourself. Platforms built for ticketing (Eventbrite, PassKit, and similar services) automatically generate a unique code per ticket, track redemption in real time across multiple gates, and can offer formats like PDF417 or Aztec if your scanning hardware supports them. Building your own validation database for a few hundred static QR codes is possible, but it quickly becomes the harder problem compared to the barcode generation itself.