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What Is a QR Code?
A QR Code (Quick Response Code) is a two-dimensional barcode that encodes data as a grid of black and white squares. Invented by Denso Wave in 1994 for tracking automotive parts, QR codes became mainstream for consumer use in the smartphone era because any phone camera can scan them instantly.
QR codes can encode URLs, plain text, phone numbers, email addresses, Wi-Fi credentials, contact cards (vCard), calendar events, and more. The amount of data they can store varies by version and error correction level, ranging from about 25 characters to over 4,000 characters.
How QR Code Generation Works
The generator encodes your data into the QR code matrix according to the ISO 18004 standard.
- Data encoding — converts your text or URL to the binary representation specified by QR code encoding modes
- Error correction — adds redundancy data allowing the code to be read even if up to 30% is damaged or obscured
- Output format — export as PNG for digital use or SVG for scalable print use
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Generate a QR Code →When To Use QR Code Generation
QR codes are useful wherever you want to bridge physical objects with digital content.
- Marketing materials — add QR codes to flyers, posters, and packaging linking to product pages or promotions
- Restaurant menus — link to digital menus or ordering systems from table QR codes
- Events — embed Wi-Fi credentials, schedule links, or check-in URLs in event materials
Frequently Asked Questions
What is error correction in QR codes?
QR codes support four error correction levels: L (7% damage tolerance), M (15%), Q (25%), and H (30%). Higher error correction adds more redundant data, making the code more resilient but larger. Level M is a good default. Level H is used when the QR code will be printed on surfaces that may get damaged, like stickers.
Can QR codes expire?
QR codes themselves do not expire — the image is permanent. However, if the code encodes a URL, the URL can expire or the server can go down. Dynamic QR codes (where the code redirects through a redirect service) can be updated to point to different URLs without reprinting, but they depend on the redirect service staying active.
What is the maximum amount of data a QR code can store?
The maximum capacity of a QR code depends on the data type and error correction level. At the lowest error correction (L), a QR code can store: 7,089 numeric characters, 4,296 alphanumeric characters, 2,953 bytes of binary data, or 1,817 Kanji characters. Smaller codes are faster to scan, so keep encoded data as short as possible.