QR codes remain the fastest way to take a user from the physical world (poster, label, screen) to a website, WiFi network or contact. This guide covers how to create professional QR codes, which formats to choose and how to avoid readability issues.
What is a QR code for?
A QR code stores information in a grid of squares that any smartphone camera can read instantly. Common uses include:
- URLs: send users to a landing page, menu, signup or download.
- WiFi: share SSID and password without typing (WPA standard).
- Contact cards (vCard): save name, phone and email to the address book.
- Email or SMS: prefill recipient and subject or body.
- Events (iCal): add an event to the calendar.
In development, QR codes are used in mobile apps (two-step login, payments), ticketing or to link physical objects to cloud resources via a unique URL.
QR types and capacity
Standard QR codes have limited capacity depending on mode (numeric only, alphanumeric, binary or Kanji). Long URLs or ones with parameters (e.g. UTM) produce denser codes. A QR generator that lets you choose error correction (L, M, Q, H) helps: level H tolerates more damage or dirt but produces a denser code.
Design best practices
- Contrast: light background and dark modules (or the reverse, consistently). Avoid busy backgrounds behind the code.
- Minimum size: for print, at least 2–2.5 cm per side; on screen, make it easy to frame with the camera.
- Quiet zone: leave a white margin around the code; don’t crop to the module edge.
- Test: scan with several phones and in real conditions (light, angle) before large print runs.
How to generate your QR code
You can use an online QR code generator that supports URL, WiFi, vCard, etc. and lets you download PNG, SVG or JPEG. That gives you a file ready for print or to embed in your site or app. If the content is a long URL with many parameters, shortening it or using a redirect keeps the QR simpler and more readable.