What a QR code is

A QR code ("Quick Response code") is a 2D barcode invented by Denso Wave in 1994 for car-parts tracking on a Toyota production line. It encodes up to ~3 kB of data — far more than the 1D barcodes that came before — and can be read from any angle at distances impractical for traditional barcodes. The COVID-19 era cemented QR codes as the default way to bridge physical and digital: scan a menu, an event ticket, a restaurant payment, a WiFi network.

What this tool generates

Pick the content type; the QR encodes the right standard format under the hood so phone cameras handle it natively:

• URL — the most common case. Plain https://example.com link.
• vCard contact — name, phone, email, organisation, website. Scanning saves directly to the phone's address book.
• WiFi credentials — WIFI:T:WPA;S:ssid;P:password;;. Guest scans the QR; the phone auto-joins.
• SMS / email / phone call / WhatsApp — pre-filled message; user just hits send.
• Plain text — for cases where you want to show a string (event code, voucher, etc.).

Customisation options

• Size — from 200×200 (web display) to 2000×2000 (print). Vector SVG output for unlimited scaling.
• Error-correction level — L (7% redundancy, smallest), M (15%, default), Q (25%), H (30%, largest, useful for logo overlay). Higher levels make the QR more readable when partially obscured or damaged.
• Foreground / background colour — for branded QRs. Maintain at least 50% contrast (the contrast checker can verify) — low-contrast QRs often fail to scan on older phones.
• Logo overlay — drop your brand mark in the centre. Error-correction H lets the code survive ~30% obscured area, so a small logo works.
• Margin (quiet zone) — the white border around the QR. Phones expect at least 4 modules of quiet zone; many printers crop too tight and break scannability.

Why use QR codes

• Menus — restaurants printed permanent QR codes during COVID and never went back. One QR per table, link to the current menu, no laminating.
• Payment — for cash businesses, link to a Venmo / PayPal / Square / WhatsApp Pay deep-link.
• Business cards — vCard QR on the back of the card; scan saves directly to contacts.
• Event tickets — encode the ticket ID; scanner reads at the door.
• WiFi for guests — print a poster; guests scan and join without typing the password.
• Loyalty programs — pair with the loyalty-card tool for full stamp/redeem flow.
• Marketing campaigns — use a UTM-tagged URL so analytics can attribute QR-driven traffic.

Common mistakes to avoid

• Low contrast. Light-grey-on-white QRs print well but scan poorly. Aim for at least 50% contrast.
• Too small to scan. Phones need ~2 cm of QR per metre of scanning distance. A 2 cm QR on a sign across a room won't scan.
• No quiet zone. Print at least a 4-module white border around the QR; many printer drivers crop too tight.
• Encoded short-link with expiry. Some URL shorteners expire links. Use a permanent URL or a redirect under your own domain.