Shipment reference
FROM
Example Supply Co. Example City, US
TO
Example Customer Co. Example Town, US
Reference: PO-1001
CODE128Preparing barcode...
Entered identifier / no postage suppliedDOCUMENTS & LABELS
Barcode & SSCC Logistics Label Generator
Prepare a single 4 x 6 inch label PDF and a barcode SVG using an internal reference or an already allocated GTIN or SSCC.
Barcode & logistics label
One entered identifier / 4 x 6 inch PDF
Encode a reference or an already assigned GTIN. A checksum is not proof of GS1 allocation or ownership. Verify printer output and scanner readability before operational use.
LABEL PREVIEW101.6 x 152.4 mm
BEHIND THE NUMBER
How the calculation works
The established bwip-js encoder builds the symbols locally. Internal Code 128 accepts up to 18 printable ASCII characters. EAN-13, UPC-A, ITF-14, and SSCC require full identifiers with valid check digits; leading zeros are retained. SSCC mode encodes only AI (00), using a nominal 0.5 mm X dimension, at least 31.75 mm bars, and quiet zones. One PDF means one label; SSCCs are not incremented or assigned.
GTIN/SSCC check digit = (10 - alternating 3/1 weighted digit sum modulo 10) modulo 10; GS1-128 encodes SSCC under AI (00), including FNC1
When this calculation helps
Generate a symbol only from an identifier already assigned through your authorized process. Internal Code 128 references and GS1 logistic-unit identifiers serve different identification purposes.
Check the interpretation
A label PDF is not postage, a carrier routing label, or GS1 certification. Preserve actual print size and quiet zones and verify the physical output. Reprinting an SSCC should identify the same logistic unit; this generator does not allocate or increment numbers.
Use identifiers assigned through your own authorized process. Checksum validation is not ownership, allocation, uniqueness, print-quality, or GS1 certification. A logistics label is not a carrier postage or routing label. Print the PDF at actual size without fitting, preserve quiet zones, and verify the physical print with appropriate scanning/verification equipment. Reprints of an SSCC must identify the same logistic unit.
GS1 Logistic Label Guideline: SSCC, GS1-128 and print dimensionsGood to know
Does the site issue GS1 numbers?
No. Enter a complete GTIN or SSCC already allocated under your own process. The examples must not be used to identify a real shipment.
Is the SVG the whole shipment label?
No. The SVG contains the barcode and readable identifier. The PDF contains the full single-label layout, including entered address and reference text.