You've seen them everywhere. On the back of cereal boxes. Taped to the window of a local coffee shop. Even floating across your TV screen during the Super Bowl. They look like a chaotic digital crossword puzzle or a glitchy piece of modern art. If you've ever wondered what are those square codes called, you're definitely not alone, even though they've been around for decades.
They are QR codes.
Specifically, "Quick Response" codes. Honestly, it’s a bit of a miracle they are still here. Back in 2013, tech pundits were writing their obituaries, claiming they were clunky and destined to be replaced by something cooler. They were wrong. Today, you can't even look at a restaurant menu without scanning one.
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The Secret History of the QR Code
These aren't just fancy barcodes. While a standard barcode—the kind you see on a pack of gum—only holds information horizontally, a QR code stores data both vertically and horizontally. This is why it's a "two-dimensional" or 2D barcode.
It was invented in 1994.
Masahiro Hara, an engineer at a company called Denso Wave (a subsidiary of Toyota), was the brain behind it. He didn't create it so you could check out a digital wine list. He created it because the Japanese automotive industry was struggling. Standard barcodes couldn't hold enough information to track car parts. Workers were having to scan up to ten different barcodes on a single box just to log the contents. It was a massive waste of time.
Hara was inspired by the board game Go. He noticed how the black and white stones on the grid could represent complex patterns. This led to the iconic three-square corner pattern we see today. Those large squares are actually "position detection patterns." They tell your phone’s camera exactly where the edges of the code are, which is why you can scan a QR code even if you're holding your phone at a weird, shaky angle or if the code is upside down.
Why Do They All Look So Different?
Not every QR code is just a link to a website. Some are tiny and simple; others are dense and look like a swarm of bees. This depends on how much data is shoved inside.
The smallest version is a 21x21 pixel grid, known as Version 1. The largest? That's Version 40, which is a massive 177x177 grid. A Version 40 code can hold up to 4,296 alphanumeric characters. That is roughly the length of a very long email or a short blog post, all tucked into a single square image.
Then there’s the error correction. This is the real magic.
QR codes use something called Reed-Solomon error correction. It's the same math used to make sure CDs and DVDs play even if they have a few scratches. Because of this, you can rip a hole in a QR code or smudge it with grease, and it will still work. In fact, you can destroy up to 30% of the code and your phone will still figure out what it's supposed to say. This is why companies can stick their logo right in the middle of a code without breaking the link.
The Great QR Code Renaissance
For a long time, QR codes were a joke.
To use one in 2012, you had to go to the App Store, download a sketchy "QR Scanner" app that was usually full of ads, wait for it to load, and then hope it worked. It was faster to just type the URL into your browser.
Everything changed in 2017. Apple finally integrated a QR scanner directly into the iOS camera app. Android followed suit. Suddenly, the friction was gone. Then the pandemic hit in 2020, and the world became terrified of touching physical menus or paper tickets. The QR code went from a "failed" tech experiment to an essential utility overnight.
Common Varieties You Might Encounter
- Static QR Codes: These are permanent. The information is encoded directly into the pattern. If the URL it points to breaks, the code is dead forever. You can't change it.
- Dynamic QR Codes: These are the smart ones. The code points to a short "redirect" URL. This means you can print the code on 10,000 flyers and then change the destination link later without needing to reprint anything. Most businesses use these because they also track data, like how many people scanned it and where they were.
- Micro QR: Used on small electronics where space is tight. It only has one orientation square instead of three.
- Design QR: These use colors, rounded dots, and brand logos to make them look less like a robot's fever dream and more like a piece of marketing.
Security: Can a Square Code Hack Your Phone?
This is a valid concern. Honestly, a QR code is just a shortcut. It’s no more or less dangerous than a link in an email.
The risk is called "Quishing"—QR Phishing. A bad actor might stick a fake QR code over a real one on a parking meter. When you scan it to pay, you're actually sending your credit card info to a scammer in another country.
Always check the URL that pops up on your screen before you click "Open." If the website looks like a string of random gibberish or isn't using "https," close the tab. Modern phones are pretty good at sandboxing these links, but they can't stop you from typing your password into a fake site.
How to Make One Yourself (For Free)
You don't need to be a coder. You don't even need to pay a subscription.
If you use Google Chrome, you can right-click any page and select "Create QR Code for this page." It even puts a little dinosaur in the middle. For more control, sites like QR Code Monkey or Bitly allow you to generate them for free.
They are incredibly useful for things that aren't marketing.
- WiFi Access: You can generate a code that automatically connects guests to your home WiFi. No more reading out a 20-character password.
- Digital Business Cards: A code on the back of your phone can instantly add your contact info to someone else’s address book.
- Inventory: Stick them on storage bins in your garage so you know what's inside without opening them.
The Future of the Square
What’s next? We are already seeing "Augmented Reality" QR codes. Imagine scanning a code on a movie poster and having a 3D trailer play right on top of the paper.
We’re also seeing the rise of "Standardized QR" for payments. In countries like Brazil, India, and China, the QR code has basically replaced the credit card. Services like Pix and Alipay have made "what are those square codes called" a question nobody asks anymore because they are the foundation of the entire economy.
They aren't going anywhere. They are too cheap to produce and too reliable to ignore.
Actionable Steps for Using QR Codes Safely and Effectively
- Inspect the Sticker: Before scanning a code in public (like on a parking meter or at a bus stop), run your finger over it. If it feels like a sticker placed over another surface, don't scan it. It might be a malicious overlay.
- Preview the Link: Use your phone’s native camera app. It will show you a preview of the URL. If the URL doesn't match the business you are at, walk away.
- Use Dynamic Codes for Business: If you are printing codes for work, always use a dynamic generator. This allows you to fix typos or update links without wasting money on a new print run.
- Don't Overcrowd: If you're creating one, keep the data light. The more text you put in a static QR code, the smaller the dots get, making it much harder for older phones to read.
- Contrast is Key: Always use a dark color for the code and a light color for the background. Inverting the colors (white code on black background) can confuse many scanners.