QR codes get less reliable as they get more interesting. A logo can cover data. Weak colors lose contrast. A small quiet zone can confuse a camera. A pattern can look great on a laptop and fail on a printed card.
QR Code Llama checks the design before export.
It supports links, text, email, phone, messages, and Wi-Fi networks. Users can change the module shape, finder eyes, colors, gradients, frame, logo, error correction, and quiet zone.
After rendering, the app rasterizes the code in memory at three representative sizes. A local decoder reads each version and compares it with the requested payload. That catches common failures before the file leaves the browser. The payload, logo, and decoded result do not need an application server.
The same renderer powers the preview and PNG, JPEG, WebP, and SVG exports. The file you download comes from the version that was checked.
That check cannot mimic every phone, printer, material, camera angle, or lighting condition. Important codes still need a test with physical devices. The app gives contrast and quiet-zone guidance without pretending a browser check can guarantee the real world.
The open-source starter keeps generator types, payload builders, design settings, rendering, and export code separate, so adding a QR type does not mean copying an entire page.