How this QR code generator works
This encodes whatever text or link you enter into a standard QR code, drawn directly in your browser using a well-established open-source QR encoding library - nothing you type is sent to a server. You can choose the output size and the error-correction level, which controls how much of the code can be damaged or obscured (for example by a logo overlay) while still scanning correctly - higher levels add more redundancy at the cost of a slightly denser code.
Why error correction is a trade-off, not a free upgrade
QR codes work by encoding your data with built-in redundancy, so a scanner can still read it correctly even if part of the code is damaged, dirty, or covered. Higher error-correction levels add more of this redundancy data, which makes the code more resilient to damage - but also makes the resulting pattern visually denser, which can make it slightly harder to scan at very small physical sizes. The right level depends on how and where the code will actually be used.
Why QR codes can encode more than just URLs
A QR code simply stores text - what a scanning app does with that text depends on recognized formatting conventions. Prefixing a phone number with "tel:" or an email address with "mailto:" follows standards that most modern scanner apps recognize, triggering a call or email action directly rather than just displaying plain text.
Why keeping the encoded text short matters
While QR codes can technically hold a few thousand characters, longer text produces a visually denser pattern that's genuinely harder for cameras to scan reliably, especially at smaller print sizes or from a distance - using a shortened URL instead of a long one is a simple, common way to keep the resulting code cleaner and more reliably scannable.