QR Code Generator

Error correction determines how much of the QR code can be damaged, dirty, or obscured (like by a logo overlay) and still scan correctly. L recovers about 7% data loss, M about 15%, Q about 25%, and H about 30%. Higher levels add more redundant data, which makes the code visually denser for the same content — M is a reasonable default for most uses; use H if the code will be printed small or partially covered.

Yes — QR codes have 40 'versions' (sizes), and the maximum capacity depends on the error correction level and content type. At the highest version with low error correction, a QR code can hold roughly 4,296 alphanumeric characters or 2,953 bytes of binary data; at high error correction, considerably less. This generator automatically picks the smallest version that fits your content.

Common causes: too little quiet-zone margin around the code (make sure there's white space border when placing it in a design), insufficient contrast between foreground and background colors, the code printed too small relative to how far away it'll be scanned from, or a phone camera app that doesn't have QR scanning enabled. As a rule of thumb, print at least a 1-inch (2.5cm) square code for close-range phone scanning.

Yes — scanning a QR code formatted as WIFI:T:WPA;S:NetworkName;P:Password;; will prompt most phones to join the network automatically, no typing required. Be aware the password is stored in the QR code exactly as entered and readable by anyone who scans it, so this is best for home use or controlled environments, not public display.

No — a QR code generated here encodes your text or URL directly and permanently; there's no server, account, or expiration involved, unlike some 'QR code' services that actually create a short redirect link they control. If you ever need to change where a code points, you'd need to generate and reprint a new code, since the destination is baked into the pattern itself.