Quick Answer
Testing a QR code before printing is essential — a QR code that fails to scan on printed materials wastes money and misses customers. Always test at the exact final print size with multiple phones before committing to a full print run. UnlimitedQRCodes.com generates ISO/IEC 18004 compliant codes that scan reliably on all modern smartphones.
Print one test copy at the exact dimensions you plan to use for production — not larger, not smaller. A QR code that scans at 10cm may fail at 3cm. Use the same material (laminated card, paper, vinyl) as the final product.
Open the iPhone Camera app (not a third-party scanner). Point at the QR code for 2–3 seconds. A notification should appear at the top of the screen. Tap it to open the link. Verify the destination URL is correct.
On Android 10+, use the built-in Camera app. On older Android, use Google Lens. Point at the QR code — a link should appear on screen. Tap to confirm the destination.
Download any free QR scanner app and scan again. If the code passes all three tests, it will work for all users.
Verify the linked page loads correctly on mobile, loads within 3 seconds, and is mobile-optimised. A QR code is only as good as the page it opens.
Enter any website URL to generate a QR code
Common causes: too small (increase to at least 3cm × 3cm), insufficient contrast (dark on white is most reliable), JPEG compression artifacts (use PNG or SVG, never JPEG), or the URL itself has changed since generation.
2cm × 2cm absolute minimum. 3cm × 3cm for table cards and receipts. 5cm × 5cm for window stickers. 8cm+ for outdoor signage. Download as SVG for print — it stays sharp at any size.