Learn the distinction between a GTIN identifier, its barcode representation, and a valid check digit.
Start with the failure you need to prevent
These guides are not alternate introductions to the generator. Printing guidance concerns physical modules, empty margin, distance and substrate. The logo guide concerns how recovery data interacts with functional patterns. The troubleshooting guide is for a code that already fails. The safety guide is for deciding whether an unfamiliar code should be opened at all.
Use a test in the same conditions as the decision
A browser preview can show whether an export decodes, but it cannot reproduce glossy packaging, a weak camera, an outdoor sign, or a misleading sticker. Export the final artwork, inspect its decoded payload, and test a physical proof at the expected distance. Keep the purpose of that test narrow: readability, destination accuracy, or safe handling are different questions.
Static code limits matter
A static QR image carries its payload directly. It has no redirect service, scan history, or later edit. That is useful for privacy and permanence, but it means a corrected link, password, event detail, or printed design requires a new code. Keep the source values and final file together so a later replacement is deliberate rather than guessed.
Choose the next guide by the evidence you have
If no print exists yet, begin with the pre-print checklist. If size is constrained by a sign or label, use size and distance. If branding is covering the middle, read about error correction. If a known code does not scan, diagnose the symbol and the capture conditions. If the code itself is unfamiliar, inspect the destination before opening it.
Enter your values, review the result, then use it with confidence.