Label Compliance Check

Paste ZPL, pick the rule packs and get every finding with rule ID, citation of the specification and fix - X-dimension, bar height, quiet zones, interpretation line, label size, required barcodes. The label is rendered and measured, the findings are drawn on it.

Automate this tool via the API: POST /v1/tools/label-compliance-check API docs

ZPL code

Rule packs

GS1 logistic label SSCC in GS1-128, X-dimension, bar height, text sizes Sunrise 2027 GTIN in GS1 DataMatrix or QR with GS1 Digital Link Amazon FBA FNSKU, box and pallet labels UPS MaxiCode, 1Z tracking number, 4 × 6 in UDI (medical devices) GS1 AIs (01)(11)(17)(10)(21), FDA / EU MDR FedEx basics Label sizes, PDF417, quiet zones DHL Paket basics Print formats, 203 dpi, Leitcode / Identcode

DPI

Label size comes from ^PW/^LL in the ZPL, otherwise 4 × 6 in. Choose the resolution of your printer - all millimetre values are calculated with it.

This is a pre-check against public specifications, not a certification. It does not replace carrier or retailer acceptance or a barcode verifier on the printed label (ISO/IEC 15416 / 15415).

What the pre-check covers

Carrier and retail labels are rejected for small things: an SSCC barcode with bars that are too short, a quiet zone that runs off the label, an interpretation line below 3 mm, a 4 × 6 in label printed at another size. The pre-check renders the ZPL exactly like the print, measures every field in millimetres at the chosen resolution and compares it with the rules of the selected packs. Each finding names the rule, the specification it comes from and a concrete fix.

Rule packs: GS1 logistic label (GS1 General Specifications, Logistic Label Guideline), Sunrise 2027 (2D barcode with GTIN at retail), Amazon FBA, UPS, UDI (FDA 21 CFR 801/830, EU MDR), FedEx and DHL Paket basics from their public API documentation. Results as an annotated label, a SARIF report for CI pipelines (GitHub code scanning) and JSON. A pre-check finds problems before printing - acceptance stays with the carrier, the retailer and a barcode verifier.

Related: the ZPL Linter checks syntax and printer pitfalls, the Barcode Scan-Proof reads every barcode back from the rendered label, and the Sunrise 2027 migration adds the GS1 2D code. Engine: zplCore.com.