What Codablock F is
Codablock F is a stacked (multi-row) linear symbology, built from Code 128-style row encoding, for fitting longer data onto a narrow label than a single-row linear barcode could hold. bwip-js renders it as a real 2D pixel grid (its own "renmatrix" rendering path), with each row separated by a solid separator band -- structurally different from every single-row linear symbology in this catalog, and closer in shape to MicroPDF417's own stacked layout.
Generate it now
Enter your data to see a live Codablock F preview.
Valid input
The input may be up to 25000 characters ("The input data is too long" beyond that, and a further internal limit rejects an encoded message longer than 5452 codewords, "Maximum length exceeded"). bwip-js computes its own per-row and overall symbol checksums automatically -- there is no option to supply your own.
Key options
Supported options include columns (4 to 62, default 8), rows (2 to 44, or leave unset to let bwip-js auto-fill enough rows for your data), rowheight (8 to 50, default 10), and sepheight (1 to 5, default 1). Codablock F has no includetext or height option of its own at all -- its overall size is entirely determined by these four controls, not a separate text-line or bar-height setting.
Output and printing
Export SVG for vector-precise label artwork or PNG for a quick proof.
Common uses
Codablock F suits labels that need to carry more data than fits comfortably in a single-row linear barcode, but where a full 2D symbology like Data Matrix or QR Code is not the established convention -- common in some healthcare and logistics labeling contexts.
Example
See the live preview above, seeded with a bwip-js-verified valid value.
Size guidance
Overall symbol width is driven by the column count and overall height by the row count, rowheight, and sepheight together -- adjust these four controls directly rather than a separate scale setting.
Troubleshooting
A rejected render is usually columns outside 4-62, rows outside 2-44, rowheight outside 8-50, sepheight outside 1-5, or data too long for the chosen row/column layout ("Maximum length exceeded").
Related formats
Related formats: MicroPDF417 (the other stacked/multi-row symbology in this catalog) and Code 128 (the row-encoding convention Codablock F builds on).
FAQ
Can I set a fixed print height for Codablock F the way I can for most other linear barcodes?
There is no separate includetext or height option for Codablock F -- its overall height comes from the rows, rowheight, and sepheight controls together. A caller-supplied height option was found to still change the rendered geometry through bwip-js's shared rendering step, but that is not exposed as a typed control here because the real default behavior when it is left out does not cleanly match that shared step's own literal default.