In my living room, there is a framed cross stitch, created by hand, on prominent display. It says under it "Home is where the Wi–Fi is." When guests scan the QR code, their phones connect to the home Wi–Fi network. It's a small, domestic example of how QR codes blend into our environment—practical, fast, and invisible until needed.
QR codes might seem like a product of the smartphone era—sleek, scannable, and everywhere from menus to metro stations. But the truth is, they've been around since the early '90s, quietly powering logistics before becoming a marketing tool. In this article, we're looking at what QR codes actually are, where they came from, and why they're more relevant than ever in a world where link sharing is becoming both more common and more controlled.
QR codes, short for Quick Response codes, are a type of two–dimensional matrix barcode that encode information in both vertical and horizontal directions. Unlike traditional barcodes, which are limited to a sequence of lines read left to right, QR codes use a grid of black and white squares to store data. This format allows them to hold significantly more information in a smaller space. The data is encoded using standardized encoding modes—numeric, alphanumeric, byte/binary, and kanji—which determine how the information is compressed and structured within the grid. Scanners interpret the patterns by analyzing the positioning and alignment markers, enabling fast and accurate decoding from any angle.
QR codes were invented in 1994 by Masahiro Hara, an engineer at Denso Wave, a subsidiary of Toyota. At the time, manufacturing processes relied heavily on barcodes for inventory tracking, but traditional barcodes were limited—they could only store a small amount of data and had to be scanned from a specific angle. Hara set out to design a new type of code that could hold more information and be read more efficiently. The result was the QR code: a compact, two–dimensional system capable of encoding large datasets, readable from any direction, and equipped with error correction to remain functional even when partially obscured. Though it was designed for industrial use, its versatility set the stage for a much broader future.
Initially designed for industrial logistics, QR codes gradually found their way into public life. As smartphones became widespread and equipped with cameras, the ability to scan QR codes moved from the warehouse floor to consumers' pockets. Their adoption accelerated during the COVID–19 pandemic, when contactless interactions became essential. Suddenly, QR codes were everywhere—replacing physical menus, enabling quick check–ins, and streamlining access to digital content. What was once a specialized tool for tracking car parts became a universal interface between physical spaces and online information.
Despite their convenience, QR codes come with inherent risks. When scanned, a QR code can automatically open a URL or trigger an action, but users can't see what that action is beforehand. This makes them a perfect delivery system for phishing attempts, malicious websites, or spoofed login pages. Unlike visible links, there's no opportunity to hover, preview, or assess the legitimacy of what you're about to open. The very simplicity that makes QR codes so useful also makes them vulnerable to abuse. Trust becomes the weakest point.
One of the less obvious uses of QR codes is their ability to disguise links in a physical format. Since the actual URL is hidden behind the pattern, QR codes can be used to share content discreetly—especially in situations where direct links might be filtered, blocked, or scrutinized. By turning a URL into a scannable image, users can bypass digital gatekeepers and share links in environments that rely on analog interactions, like posters, flyers, or business cards. It's a form of stealth communication: the link is there, just not in plain sight.
QR codes may have started as an industrial solution, but they've evolved into a widespread and often invisible layer of our digital lives. Their strength lies in their simplicity and adaptability—able to hold complex information in a compact, scannable form. But that same simplicity also creates ambiguity. Without visibility into what a QR code actually does, users are forced to trust the source. As QR codes continue to be used for both convenience and covert sharing, it's worth remembering: the code is only as safe as the intent behind it.