The long, skinny rectangle of stripes on a boarding pass — or on the back of your driver's license — isn't a QR code. It's a PDF417 barcode. Both pack data into a small printed area, and both are "2D" barcodes, but they were built for different jobs. That's why one shows up on a plane ticket and the other on a restaurant table.
Here's what each format is, how they differ in capacity and shape, and why airlines and motor-vehicle agencies landed on PDF417.
The short answer
PDF417 is a wide rectangle made to hold a lot of text in a thin strip and to be read by older laser scanners as well as cameras. A QR code is a square made for fast, any-angle scanning by a phone camera — usually to open a link. Boarding passes and IDs use PDF417 because the industry standards spell it out. Everyday menus and posters use QR because phones read it in an instant.
What PDF417 is
PDF417 is a stacked linear barcode, invented at Symbol Technologies back in 1991. The name comes from its building block: every pattern is 4 bars and spaces, 17 units wide. A symbol is really a stack of rows, and one PDF417 code can hold up to 1,850 alphanumeric characters, 2,710 digits, or 1,108 bytes. It leans on Reed-Solomon error correction and is defined in the ISO/IEC 15438 standard.
What a QR code is
A QR code is a matrix barcode that Masahiro Hara designed at Denso Wave in 1994. Those three big squares in the corners are finder patterns — they let a scanner spot the code and figure out its orientation from any direction. The largest version holds up to 4,296 alphanumeric characters, 7,089 digits, or 2,953 bytes, with four error-correction levels recovering roughly 7% to 30% of a damaged code, per Denso Wave's own specification.
Capacity and shape, side by side
A maxed-out QR code actually holds more than a PDF417 symbol — but raw capacity rarely settles the matter. Shape does. PDF417 is rectangular, so it fits along the bottom strip of a boarding pass or the back of a card. Its rows can be read by a single-line laser scanner sweeping across them, which still matters at gates and counters running older hardware. A QR code, by contrast, needs a camera or imager that takes in the whole square at once — exactly what a phone does well.
Why boarding passes and licenses use PDF417
Aviation runs on IATA's Bar Coded Boarding Pass standard, which specifies PDF417 for printed passes and has been mandatory for member airlines since 2010. The same standard allows Aztec, QR, and Data Matrix for mobile passes on a phone screen — which is why your digital pass might look square while the paper one is a long rectangle.
Driver's licenses follow a different rulebook. The AAMVA card-design standard requires a PDF417 barcode on the back of licenses and ID cards across nearly every US state and Canadian province. It stores your name, address, date of birth, and license number in a fixed field layout that a reader can pull without any internet connection. That offline, self-contained quality is a big part of why PDF417 stuck for identity documents. If you want a wider take on when each symbology makes sense, see our guide on QR codes versus barcodes.
What your phone can read (and where QRDock fits)
Modern phone cameras can read both formats, though the built-in scanners are mostly tuned for QR links. A dedicated scanner helps when you actually need to read the PDF417 on a license or a pass. QRDock reads ten formats — including PDF417, QR, Aztec, and Data Matrix — and runs a URL safety check before you open any web link a code points to. It doesn't track what you scan, and it shows no ads. To decode the barcode on a pass or card, open QRDock, point the camera, and it'll tell you which format it found.
FAQ
Is the barcode on my boarding pass a QR code?
Usually no. Printed boarding passes use PDF417 — that wide rectangle of stripes specified by IATA. Mobile passes on your phone may use QR, Aztec, or Data Matrix instead.
Can my phone scan a PDF417 barcode?
Yes. A phone camera can read PDF417, but many built-in scanners focus on QR links. A scanner app like QRDock reads PDF417 directly.
Which holds more data, PDF417 or QR?
A maximum-size QR code holds more — about 4,296 alphanumeric characters versus 1,850 for PDF417 — but most documents use far less than either limit, so shape and scanner compatibility usually decide the choice.
Why is a driver's license barcode a long rectangle?
Because the AAMVA standard specifies PDF417, a rectangular format that fits the back of a card and stores the cardholder's details so a reader can retrieve them offline.