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Direct answer
UseCOS generates permanent static QR codes adhering to the international ISO/IEC 18004 standard. Your target data (URL, WiFi password, vCard contact, or text) is encoded directly into the black-and-white 2D matrix pattern. It contains zero redirect URLs, requires no subscription, and will work forever without expiring.
Create high-resolution URL, WiFi, vCard Contact, and Email QR codes. Pure static standard format that never expires with zero subscription scams.
Direct static link. Scans open immediately without passing through third-party redirect trackers.
Most commercial QR code generators operate on a “bait-and-switch” model. When you generate a QR code, they encode a temporary redirect link (e.g., https://qr-tracker.com/xyz123) instead of your real website or contact info. After a 14-day free trial, they disable the redirect and demand $15 to $50/month to keep your printed flyers, product packaging, or restaurant menus active.
| Feature | UseCOS Static QR | Commercial “Dynamic” QR |
|---|---|---|
| Expiration Date | Never Expires (Permanent) | Expires after trial (14–30 days) |
| Privacy / Data Route | Direct to destination (Zero intermediary) | Routes through 3rd-party tracking server |
| Subscription Required | $0 Forever (100% Free) | $10 – $40/month ongoing |
| Offline Scanning | Works offline (WiFi, vCard, Text) | Fails without active internet connection |
QR codes use Reed-Solomon mathematical error correction to ensure your code scans reliably even if smudged, scratched, or partially obstructed by a logo:
Engineering standards based on optical focal length and the 10:1 distance-to-size ratio rule.
| Medium / Placement | Scanning Distance | Minimum Dimensions | Error Correction | Print & Substrate Guardrails |
|---|---|---|---|---|
| Business Card / Pocket Pass | 15 – 20 cm (handheld) | 2.0 × 2.0 cm (0.8" × 0.8") | Level M (15%) | Never print smaller than 2×2 cm. Maintain at least 4 modules of white quiet-zone padding around the edges. |
| Restaurant Table Tent / Menu | 30 – 50 cm (seated) | 3.5 × 3.5 cm (1.4" × 1.4") | Level M or Q (25%) | Avoid high-gloss lamination that creates optical glare under restaurant spotlights. Use matte UV coating. |
| A4 / Letter Flyer & Poster | 1.0 m (arm's length) | 10.0 × 10.0 cm (4.0" × 4.0") | Level Q (25%) | Optimal size for eye-level community boards and shop windows. Ensure high contrast against background artwork. |
| Rollup Banner & Trade Show Booth | 2.0 – 3.0 m (walking) | 25.0 × 25.0 cm (10" × 10") | Level H (30%) | Position at chest height (1.2m–1.5m from floor). Codes near floor level are awkward and difficult to scan. |
| Stage Backdrop & Presentation Slide | 5.0 – 15.0 m (audience) | 50.0 – 150.0 cm (screen) | Level L or M | Keep on screen for at least 20 seconds. Use short URLs to minimize dense pixel grid clustering on LED projectors. |
📶 WiFi Network Access
WIFI:T:WPA;S:NetworkName;P:Password;;
Instantly joins phones to WiFi without typing passwords.
📇 vCard 3.0 Contact
BEGIN:VCARD\nVERSION:3.0\nFN:John Doe...
Adds direct contact card into iOS Contacts and Google Contacts.
Because static QR codes encode data immutably into the matrix, always test-scan your QR code on at least two different smartphones before sending items to bulk commercial printing. Once printed, a URL typo cannot be modified remotely.
UseCOS executes 100% of QR rendering in your local browser engine. Payloads, contact vCards, and WiFi credentials never transit or store on our servers.
Built in compliance with ISO/IEC 18004 2D Barcode Symbology Specifications.
Authored by UseCOS Research & Engineering.