QR Code Generator

QR Generator turns structured input — a URL, a WiFi credential, an email draft, a vCard contact — into a scannable QR image entirely inside your browser. Under the hood it uses the qrcode npm library: QRCode.toCanvas writes the matrix to a 2D HTMLCanvasElement and QRCode.toString produces an SVG version on demand. There is no API call. The encoded data exists only in this tab's memory until you download it.

The seven supported types map to formal payload formats that mainstream camera apps already understand. URL is plain "https://...". Email becomes a mailto: link with URL-encoded subject and body. Phone uses tel:, SMS uses sms: with a body parameter, and WiFi follows the WIFI:T:WPA;S:NetworkName;P:secret;; convention parsed by iOS, Android, and most third-party scanners. vCard is built as a VERSION:3.0 record with FN, TEL, EMAIL, ORG, and URL fields — when a phone scans it, the OS offers to add the contact directly.

QR symbols come in 40 versions; the qrcode library picks the smallest version that fits the data at the chosen error correction level. The hard ceiling at level L is 4,296 alphanumeric characters or 7,089 numeric digits, falling to about 1,852 alphanumeric at level H. The character counter under the Text input warns when you cross 90% of that ceiling, because shorter payloads produce sparser matrices that scan faster and from further away.

Error correction trades capacity for resilience. L (~7%), M (~15%), Q (~25%), and H (~30%) describe how much of the printed code can be obscured before the message becomes unrecoverable. M is the default here because it is the standard balance for screen-displayed QR codes; raise it to H if you intend to overlay a logo using the customizer or to print on a surface that may scuff.

Export goes through the same canvas. PNG download is just canvas.toDataURL('image/png'). SVG is a separate render through QRCode.toString, blob-wrapped, and given a temporary object URL via URL.createObjectURL. Copy uses the modern Clipboard API — navigator.clipboard.write with a ClipboardItem — and falls back to a download on browsers without that capability. Share calls navigator.share when available so the code can be sent directly to AirDrop, Messages, or Drive on supported devices.

Print uses window.open with an inlined data-URL <img> and an onload-triggered window.print, which produces a clean print preview without any header or footer chrome. The popup will be blocked if browsers consider it not user-initiated; clicking the Print button after a generated preview always counts as user-initiated so this is rarely an issue in practice.

Static QR codes carry their data in the symbol itself, so the URL or text inside cannot be changed after the code is printed. If you need redirectable codes (so the destination can be edited later without reprinting), generate a code that points to a short link from a service you control, then update that link as needed.