How a QR code works
A QR code (Quick Response code) is a two-dimensional barcode that can store text, links, contact details, and other kinds of data as a pattern of black and white squares. Any phone camera with a QR reader can decode the content just by pointing at the image, no typing required.
Which size and error correction level to choose
For on-screen use (website, email, social media), 300px is usually enough. For print, especially on small materials like business cards, use 400px or 500px to keep it sharp even at lower print resolution. As for error correction, most cases work fine with level M (medium). If you plan to overlay a logo in the center of the QR code, or it will be printed on a surface prone to wear, use level H (very high), which tolerates up to 30% damage without losing readability.
Tips for a QR code that actually works
Keep strong contrast between the code color and the background — colors that are too close to each other make the code hard or impossible for a camera to read. Avoid similar tones for the two colors, and always test the generated QR code with a phone before using it in a final piece, whether digital or printed.
What kind of content can I generate
The content field accepts any text. The most common use is links (start with https://), but you can also generate QR codes for a phone number (tel:+15551234567), an email address (mailto:[email protected]), or even Wi-Fi credentials using the format WIFI:T:WPA;S:NetworkName;P:password;;.