What is a QR code? How it works and what it is used for

You have probably seen QR codes on packaging, posters, invoices or restaurant menus. But what are they, how do they work and why have they become everywhere? This guide explains everything simply, with no technical jargon.

What a QR code is

A QR code (Quick Response) is a two-dimensional barcode — a square made up of black and white modules that encodes information: a link, text, WiFi network details, a contact or even payment instructions. When you scan it with your phone camera, the information is decoded instantly.

It was invented in 1994 by the Japanese company Denso Wave for tracking car parts, but its use exploded with smartphones, especially after 2020 when digital menus and contactless payments became standard.

How a QR code works

The three squares in the corners (position patterns) help the camera identify the code's orientation. The rest of the modules encode the actual data, plus error-correction information — that is why a QR code works even when it is slightly damaged or partially covered.

The phone camera detects the code, decodes the content and performs the right action: opens a link in the browser, connects to WiFi, saves a contact or pre-fills a payment.

Types of QR codes

• Link (URL) QR code — opens a web page;
• WiFi QR code — connects the phone to the network with no password typed;
• vCard QR code — saves a contact to the address book;
• SEPA payment QR code — pre-fills a bank transfer;
• WhatsApp QR code — opens a direct conversation;
• Google Reviews QR code — sends the customer to the review form;
• File QR code — shares PDFs, images or video through a scan.

Static vs. dynamic QR code

A static code holds the information directly — simple and free, but it cannot be changed after generation. A dynamic code encodes a short link you can redirect anytime, without reprinting the code, and provides scan analytics. The full comparison is in the dynamic vs. static guide.

Are QR codes safe?

Yes, by design: a QR code is just an information container. It cannot install apps or run code on your phone. The risk only appears if someone replaces a legitimate code with one that leads to a malicious site — that is why you should always check the URL before acting. More details in the safety guide.

Create your first QR code

Generate a QR code for free, with no account, in seconds with the getQR generator. Choose the type (link, WiFi, vCard, payment), enter your data, customise the design and download — ready to print or share.