The short version
A QR code is a two-dimensional barcode that stores information: a website URL, WiFi credentials, contact details, plain text, or other data. When someone points their phone camera at it, the phone decodes the pattern and takes action: open a link, connect to a network, or save a contact.
QR code data types
One QR format, many payloads. The pattern looks similar, but what happens after the scan depends on what was encoded.
| Type | Encodes | Example use |
|---|---|---|
| Website URL | https:// link | Menus, product pages, social profiles |
| WiFi | Network name + password | Guest WiFi at cafes and offices |
| Contact card (vCard) | Name, phone, email | Business cards and networking |
| Address + subject + body | Pre-drafted support or sales emails | |
| SMS | Phone number + message | Text promos and appointment reminders |
| Phone | Phone number | One-tap call from a poster or flyer |
| Chat link with message | Customer support and bookings | |
| Plain text | Any text string | Promo codes, instructions, serial numbers |
Website URL
WiFi
Contact Card
A bit of history
Denso Wave, a Toyota subsidiary, invented QR codes in 1994 to track car parts during manufacturing. Traditional barcodes only hold about 20 characters. QR codes can store thousands, enough for a full URL, a WiFi password, or a business card.
They stayed mostly industrial until smartphones got good cameras. Around 2017 to 2020, phone makers built QR scanning directly into the camera app. During the pandemic, QR codes exploded for restaurant menus, vaccine records, and contactless payments. They stuck around because they're genuinely convenient.
How scanning works
The black and white squares aren't random. QR codes have three large corner squares that help the camera figure out orientation. The smaller modules encode your data using a standard format that any compliant reader understands.
Error correction is built in. Up to 30% of the code can be damaged or covered by a logo and it still scans. That's why you can put a small brand mark in the center without breaking functionality.
| Level | Data recovery | Best for |
|---|---|---|
| L (Low) | ~7% | Clean prints, maximum data capacity |
| M (Medium) | ~15% | General use, menus and flyers |
| Q (Quartile) | ~25% | Outdoor signage, slight wear |
| H (High) | ~30% | Logo overlay, stickers, imperfect surfaces |
Where people use QR codes today
- Restaurants: digital menus that update without reprinting
- Retail: product info, reviews, or checkout links on packaging
- Events: tickets, schedules, WiFi for attendees
- Business cards: one scan saves your full contact to someone's phone
- Marketing: trackable campaign links on posters and flyers
- Personal: WiFi sharing at home, payment links, social profiles
Ready to make one?
Our free QR code generator handles URLs, WiFi, contacts, WhatsApp, and more. Customize colors, add a logo, download as PNG or SVG. No account needed.