Util Tools What is a QR code?
A QR (Quick Response) code is a two-dimensional barcode that stores data in a grid of black and white squares. A phone camera reads it instantly, which is why QR codes are everywhere: menus, posters, packaging, tickets, and payments. This generator creates codes for URLs, plain text, email, phone, SMS, WiFi networks, vCard contacts, and map locations, with PNG or SVG download.
Error correction explained
QR codes have built-in error correction, which lets a code still scan even if part of it is dirty, damaged, or covered (for example by a logo). There are four levels, from L (about 7% recovery) to H (about 30%). Higher levels are more robust but make the pattern denser. Choose a higher level if the code will be printed small, placed somewhere it may get scuffed, or have a logo overlaid.
How much data fits in a QR code?
Capacity depends on the data type and error-correction level, but a single QR code can hold up to roughly 4,000 alphanumeric characters at the lowest correction level. In practice you should keep the content short: less data means a simpler, lower-density pattern that scans faster and more reliably, especially at small print sizes. For long links, point the QR code at a short URL.
Are these QR codes permanent?
Yes. The codes generated here are static: the data is encoded directly into the pattern, so they never expire, require no account, and keep working forever. The trade-off is that the content cannot be changed after printing, and they do not track scans. If you need editable destinations or analytics, you would need a dynamic QR service instead, but for most uses a static code is simpler and free.
最終更新日: 2026年9月