Free QR Code Generator — URLs, WiFi, Contacts & More

QR Code History and How They Work

QR codes (Quick Response codes) were invented in 1994 by Masahiro Hara at Denso Wave, a Toyota subsidiary in Japan. The original purpose was tracking automotive parts moving through manufacturing lines — the 2D barcode could be scanned quickly from any angle, encoding far more data than a traditional 1D barcode. Denso Wave released the format royalty-free, which enabled global adoption.

A QR code is a matrix of black and white squares arranged in a defined grid. Three large square alignment patterns in the corners (the finder patterns) let scanners detect the code orientation regardless of angle. The data is encoded using Reed-Solomon error correction, which means a QR code can be partially obscured or damaged and still decode correctly — this is what makes it possible to place a logo in the center of a QR code.

Smartphones began shipping with built-in QR scanners around 2017 (iOS 11 added native support via the Camera app), and the COVID-19 pandemic of 2020 massively accelerated adoption as businesses switched to QR menus, QR check-ins, and QR payment links. Today QR codes are ubiquitous in advertising, packaging, payments, and physical-to-digital experiences.

All 8 QR Code Types Explained

This tool supports eight different QR data types, each encoding information in a standard format that apps and operating systems understand natively.

URL. The most common type. Encodes a web address (including https://). When scanned, the phone opens the URL in the default browser. Use for: website links, product pages, landing pages, social profiles, payment links.

Text. Encodes plain text with no special action. When scanned, the device shows the text. Use for: serial numbers, coupon codes, reference numbers, any text that needs to be copied without opening an app.

Email. Encodes a mailto: URI with recipient, subject, and body pre-filled. When scanned, the phone opens the email client with all fields populated. Use for: feedback forms, customer support contact, newsletter signups via print materials.

Phone. Encodes a tel: URI. When scanned, the phone offers to call the number. Use for: business cards, shop windows, customer service numbers on packaging.

SMS. Encodes an smsto: URI with a pre-filled phone number and optional message. When scanned, the phone opens SMS with the number and message ready to send. Use for: two-factor authentication opt-ins, customer feedback, appointment confirmations.

WiFi. Encodes WiFi credentials (SSID, password, encryption type) in the WIFI: format standardised by the Wi-Fi Alliance. When scanned on Android 10+ or iOS 11+, the phone automatically connects to the network. Use for: guest WiFi in hotels, cafes, offices — replace the paper WiFi card with a QR code.

Contact (vCard). Encodes a vCard 3.0 with name, phone, email, organisation, website, and address. When scanned, the phone offers to save the contact. Use for: business cards — put a QR code on your card so recipients can save your details without typing.

Location. Encodes a geo: URI with latitude and longitude. When scanned, the phone opens the maps app at that location. Use for: event venues, store entrances, directions to a hard-to-find address.

Error Correction Levels Explained

QR codes use Reed-Solomon error correction to remain scannable even when partially damaged, dirty, or obscured. There are four error correction levels:

• L (Low) — 7% restoration. The QR code is smallest and easiest to scan in perfect conditions, but fails quickly if damaged. Use for digital-only QR codes displayed on clean screens.
• M (Medium) — 15% restoration. A good balance for most uses. The default in this tool.
• Q (Quartile) — 25% restoration. Good for print materials that may get dirty or folded.
• H (High) — 30% restoration. Maximum redundancy. Required when adding a logo because the logo covers the center of the code. Codes are larger and slightly slower to scan. Always use H when embedding a logo.

Higher error correction levels produce larger, denser QR codes. For logos specifically: the logo should cover no more than 20–30% of the QR code area, and H error correction must be used. The redundant data allows the scanner to recover the missing bits covered by the logo.

QR Code Size Guidelines

The minimum scannable size of a printed QR code depends on the scanning distance and the density of the code (which increases with data length and error correction level). As a general rule:

• • Minimum print size: 2×2 cm (about 0.8 inches) for close-range scanning on smartphones
• • Business card: 2.5×2.5 cm minimum, 3.5×3.5 cm recommended
• • Poster / flyer: 4×4 cm minimum for reading at arm's length (60–90 cm)
• • Billboard / large signage: Scale proportionally — roughly 1 cm per 10 cm of viewing distance

For digital display, the minimum resolution is 200×200 pixels for on-screen QR codes. Download the SVG version for print materials — SVG scales to any size without pixelation, so you can use a single file for both a business card and a billboard.

QR Code Best Practices

Contrast is critical. The dark modules must have high contrast against the light background. Black on white is ideal. Avoid light-on- light or dark-on-dark combinations — even pastel colour combinations with insufficient contrast will fail to scan on many devices.

Preserve the quiet zone. QR codes require a white margin around the code equal to at least 4 modules wide. This "quiet zone" helps scanners detect the boundary of the code. The margin slider in this tool controls this. Never crop the quiet zone when placing a QR code in a design.

Test before printing. Always scan the generated QR code with multiple devices (iPhone, Android) and multiple apps (Camera app, dedicated QR scanner) before committing to print. A QR code that looks correct visually may still fail to decode if the data is malformed or the contrast is insufficient.

Keep URLs short. Longer data = more modules = smaller modules = harder to scan. If you are encoding a long URL, use a URL shortener first to reduce the data density. This also makes the QR code scan faster and more reliably at small print sizes. Use the QR Reader to verify your generated codes scan correctly.

Static vs Dynamic QR Codes

Static QR codes encode data directly and permanently. To change the destination, you must generate a new QR code and replace all printed copies. This tool generates static QR codes.

Dynamic QR codes encode a short redirect URL that points to a redirect service. The destination can be changed at any time in the service dashboard without reprinting. Dynamic codes also typically include scan analytics. However, dynamic QR codes require a paid subscription to the redirect service, and if the service shuts down, all your QR codes stop working permanently.

Are static QR codes free forever? Yes. Static QR codes encode their data directly and require no subscription, no service, and no ongoing payment of any kind. They will scan correctly forever, regardless of what happens to any website or service. This is the format generated by this tool — free, permanent, and with no dependency on any third-party service.