Data Capacity
Data capacity is how much data a barcode symbology can hold, bounded differently for linear codes (grows with symbol width) and 2D codes (fixed by version and error-correction level).
What You Need to Know
For linear symbologies, capacity is open-ended in the standard but limited in practice: a Code 128 symbol may legally be as wide as the label allows, but scanner optics, printer resolution, and decoding confidence cap useful length — tens to roughly a hundred characters. Fixed-length retail codes (EAN-13 = 13 digits, UPC-A = 12) are the opposite extreme: exact, and carrying no free-form data at all.
2D symbologies define versions: QR Code Versions 1-40 scale from 21×21 to 177×177 cells, holding up to 7,089 digits or 4,296 alphanumeric characters at the lowest correction level; Data Matrix holds up to 2,335 characters; PDF417 up to 1,850. Capacity also interacts with character set — numeric modes in QR pack digits three-per-ten bits, byte mode far less densely — so encoding "12345" and "HELLO" of the same length consumes different symbol real estate.
Where Data Capacity Applies
The dominant 2D matrix barcode: up to 7,089 digits in a square symbol with selectable error correction.
Generate QR Code →A compact 2D matrix code with fixed Reed-Solomon error correction — the standard for pharma serialization and tiny parts.
Generate Data Matrix →A stacked-linear 2D code carrying up to 1,850 text characters — the workhorse of IDs, boarding passes, and transport documents.
Generate PDF417 →A high-density, variable-length linear barcode that encodes all 128 ASCII characters, and the backbone symbology of modern logistics.
Generate Code 128 →