Troubleshoot a QR code that will not scan by checking the white border, image proportions, content density and the downloaded or printed version.
Separate recognition from destination problems
First determine whether the scanner recognizes the code at all. If it displays the correct address but the page will not open, investigate the destination link or access requirements. A broken website address is different from an unreadable QR pattern.
If the scanner cannot recognize the pattern, compare the displayed or printed image with the original PNG. Look for a missing border, stretching, blur, reflections or parts of the code covered by other design elements.
Keep the square shape and white border
ToolNivo generates a square black-on-white PNG with a white margin around the code. Keep that margin when placing the image in a document or design. Cropping tightly against the dark pattern can make it harder for a reader to distinguish the code from its surroundings.
Resize proportionally if you need to change its display size. Do not stretch it into a rectangle or place it over a busy photograph. Use the downloaded PNG rather than a small screenshot that may introduce blur or cut off part of the border.
Check size, lighting and content density
Try scanning from a different distance so the camera can focus. Reduce glare on a screen or glossy print and make sure the entire code is visible. A very small code may require a larger placement, especially when the input produces a dense pattern.
Shorten the encoded content when possible. For a website, use the correct direct address without unnecessary additions. Do not delete required parameters merely to make a shorter string; confirm that the simplified link still reaches the intended page.
Test a realistic sample before sharing widely
Download a fresh PNG from the generator and try it on a second device or scanner if one is available. For printing, make a single sample at the intended physical size. Examine whether dark areas have merged, edges have become fuzzy or the printer has clipped the margin.
A code that works on a large monitor is not automatically suitable for a small printed label. Keep testing the final placement rather than only the original preview. Once recognition works, verify the decoded link or text as a separate final check before distributing more copies.