Supporting Guide

Debugging Invalid Payloads: Why Good-Looking Strings Still Fail Barcode Rules

Most barcode rendering failures are not renderer bugs. They are payload mismatches: the wrong digit count for UPC-A, an unsupported character in a linear symbology, or a GS1 field sequence that breaks AI parsing rules. Debugging gets faster when you classify errors by rule family instead of by library.

• Length errors: wrong GTIN size, missing check digit, truncated serials.
• Character-set errors: lowercase or punctuation in restricted symbologies.
• Structured-data errors: missing FNC1 behavior or broken AI boundaries.

Start by validating the raw string before you inspect output geometry. In enterprise systems, payload errors should never make it to the render stage unclassified.