About QR codes
A QR code (short for "Quick Response" code) is a square, two-dimensional barcode that stores information as a grid of black and white squares. Invented in 1994 by the Japanese company Denso Wave to track car parts, it can hold far more data than a traditional barcode and can be read from any angle. Today almost every smartphone camera reads QR codes instantly, which is why they appear on posters, menus, packaging, tickets, business cards and payment screens everywhere.
What you can put in a QR code
QRBloom builds the most common types for you. A URL opens a website when scanned.
Text shows a plain message. Wi-Fi lets a guest join your network
without typing the password. Email, phone and SMS
codes start a message or call with one tap. Behind the scenes these are just short pieces of
specially formatted text — for example, a Wi-Fi code looks like
WIFI:T:WPA;S:MyNetwork;P:password;;.
Error correction and quiet zones
QR codes include built-in error correction, so they still scan even if part of the code is dirty, creased or covered by a small logo. Higher levels (Q or H) survive more damage but make the code denser. The empty border around a code — the "quiet zone" or margin — matters too: keep at least a few modules of space so scanners can find the code reliably.
Tips for codes that always scan
Keep good contrast between the foreground and background (dark on light works best), avoid inverting the colours, and print or display the code large enough for the scanning distance. When in doubt, download the SVG version — it stays razor-sharp at any size, which is ideal for print.