Barcode Trivia
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55 free Barcode trivia questions with answers — technology quiz, new questions added Sep 2026.
This barcode trivia quiz tells the whole story of the machine-readable stripe: Bernard Silver overhearing a grocery executive at Drexel in 1948, Joe Woodland drawing Morse code dashes into the sand at Miami Beach, the 1952 patent nobody wanted, the KarTrak railroad labels that failed, and the morning in June 1974 when a pack of Wrigley's Juicy Fruit rang up 67 cents at a Marsh supermarket in Troy, Ohio. From there it covers how a UPC actually works (12 digits, 30 bars, a check digit), the EAN and GS1 system that runs global retail, ISBNs on books, Code 39 and the US military, Code 128, Codabar on blood bags and FedEx airbills, and the two-dimensional era: Denso Wave's Go-board-inspired QR code, Data Matrix, PDF417 on driver's licenses, MaxiCode on UPS parcels and RFID tags. There are also questions on barcode scanners, the 'Supermarket Scanner That Failed', Hitman's tattoo and the people who think barcodes are the Number of the Beast. Every answer has been checked against primary sources, chiefly the Wikipedia articles on barcodes, the UPC, QR codes and their inventors, and each explanation adds one more detail. Play, see your score, and share it with the tech-history fans in your group chat.
30 of 55 questions with answers and explanations. Play the quiz
Q 01Where was Bernard Silver a graduate student when he overheard a grocery executive asking for automatic checkout?
Drexel Institute of Technology
Drexel Institute of Technology is where a grocery executive begged a dean for help in 1948; the dean refused, so Silver took the problem to his friend Woodland.
Q 02What was wrong with Woodland and Silver's ultraviolet ink system?
The ink faded too easily and was expensive
The ink faded too easily and was expensive, but Woodland was sure the idea could work, so he quit Drexel and moved to his grandfather's Florida apartment.
Q 03Woodland formed his first barcode by drawing in what?
Sand on a beach
Woodland drew the first barcode in sand on a beach in Miami: he extended Morse code dots and dashes downward into narrow and wide lines.
Q 04To read his striped code, what existing technology did Woodland adapt?
Movie soundtracks
Movie soundtracks were played by shining light through a patterned strip onto a sensitive tube, so Woodland's reader paired a 500-watt bulb with a tube taken from movie projectors.
Q 05Woodland recalled Morse code from his training with which organization?
The Boy Scouts
The Boy Scouts taught Woodland Morse code, and he later stretched its dots and dashes into the wide and narrow lines that became the barcode.
Q 06In 1932, Wallace Flint imagined an automated grocery checkout built around what?
Punch cards
Punch cards: Flint's 1932 thesis had shoppers punch cards to mark their picks for a reader, but card equipment was so bulky and costly the plan was never practical.
Q 07Which company bought Woodland and Silver's barcode patent, later selling it to RCA?
Philco
Philco bought it after the pair failed to get IBM to build a system that needed equipment still years off, and later sold the patent to RCA.
Q 08The KarTrak system of the 1960s used colored reflective stripes to identify what?
Railroad cars
KarTrak labels on railroad cars were read by trackside scanners; the Association of American Railroads made them standard in 1967 before dropping the scheme in the late 1970s.
Q 09Why did David Collins leave Sylvania to found his own barcode company?
His bosses refused new funding
His bosses refused new funding for a black-and-white code for other industries, saying their big market was enough, so Collins quit and founded Computer Identics.
Q 10Which grocery chain volunteered to test RCA's bullseye code in the early 1970s?
Kroger
Kroger volunteered as RCA's guinea pig once RCA took up bar codes after a 1966 grocery meeting, and an 18-month test began at a Cincinnati store in July 1972.
Q 11What advantage did IBM's bars hold over RCA's bullseye?
Smeared ink only made it taller, not unreadable
Smeared ink only made it taller, not unreadable: presses smear ink in the direction the paper runs, so extra ink ran off the ends of the bars instead of blurring the code.
Q 12Who refused his manager's appeal to base IBM's grocery code on the bullseye?
George Laurer
George Laurer won over IBM's skeptical bosses with a rectangular code instead, and the grocery industry's selection committee chose his design over RCA's in 1973.
Q 13What worried IBM executives at a 1971 grocery industry meeting?
Q 21Why was the 1973 UPC a bigger deal than the barcode systems before it?
Every equipped store could read it
Every equipped store could read it, because grocers and product makers agreed on one standard symbol instead of each system using its own code.
Q 22Which UK supermarket chain had Plessey shelf barcodes up and running by 1972?
Sainsbury's
Sainsbury's put the codes on its shelves, not on packs, so staff could scan each product's spot and order just enough stock to refill it.
Q 23What could Code 39 hold that a supermarket UPC could not?
Letters and digits
Crowds at RCA's booth
Crowds at RCA's booth made IBM fear losing a huge market, and then a marketing specialist remembered that the bar code's inventor, Woodland, still worked at IBM.
Q 14What was the first product ever scanned with a UPC at a retail checkout?
Wrigley's Juicy Fruit gum
Wrigley's Juicy Fruit gum was scanned first, in 1974, yet scanners spread slowly because stores gained little until most products carried the codes.
Q 15Which company installed the checkout system for the first UPC scan in 1974?
NCR
NCR fitted the new checkout, and the night before the first scan Marsh staff put bar code labels on the store's goods, since few products yet carried printed codes.
Q 16A UPC names the product and what else?
Its maker
Its maker: on most items, a firm registers once for its own company number, then gives each product an item number under it.
Q 17What is the purpose of the final numeral in a UPC?
Error-detecting check digit
The last numeral is an error-detecting check digit: scanners recompute it from the preceding digits with a weighted sum and reject a code that does not match.
Q 18Why do UPC halves draw digits differently?
So it scans in either direction
So it scans in either direction: left-hand digits use odd parity and right-hand digits even, so the scanner can tell which end it started from.
Q 19Why did Murray Eden have digits printed under the UPC's bars?
In case scanners fail
In case scanners fail: a clerk could enter the digits instead, and the selection committee also changed the digits' font from IBM's proposal.
Q 20Which consulting firm helped the grocery industry define the numerical UPC format?
McKinsey & Company
McKinsey & Company helped set the product number first; the grocery council then asked many companies, among them RCA, Singer and Pitney Bowes, to design a symbol for it.
Letters and digits, and each character checks itself, so one faulty bar can't turn it into a different valid character.
Q 24Why do box barcodes often have a black frame?
Prevent misreads
Prevent misreads: a slanting beam entering through the top or bottom edge could miss bars, and the frame also evens out printing plate pressure.
Q 25Which two kinds of paperwork used the Codabar barcode?
FedEx airbills and blood bank forms
FedEx airbills and blood bank forms used it, as do many libraries; Codabar checks itself, so it needs no extra check digit to catch misreads.
Q 26EAN-13, the barcode used outside North America, is a UPC-A with what added?
A country prefix
A country prefix: that extra digit let each nation flag its own codes, so the same symbol spread worldwide under local names such as Japan's JAN.
Q 27Why do book barcodes start 978 or 979?
So ISBNs fit in
So ISBNs fit in: a book's barcode carries its ISBN digits, sparing shops a second, parallel numbering system.
Q 28Which country's book trade began the nine-digit Standard Book Number that became the ISBN?
Britain
Britain: a 1966 report for the UK book trade by statistician Gordon Foster set out the scheme, and ISO then adapted the British number for worldwide use.
Q 29Apart from the title and edition, what does part of every ISBN identify?
The publisher
The publisher, or imprint; the title part is unique to each edition and format, so a book's hardback and paperback get different numbers.
Q 30Before Apple's iOS 11 in 2017, what did iPhone owners usually need to scan a QR code?
A separate reader app
A separate reader app: iOS 11's own camera began reading the codes by default, popping up the link with no extra software needed.