GS1-128 Barcode Generator
Generate a GS1-128 barcode for logistics and supply chain labels from GS1 application identifiers such as (01) GTIN, (10) batch, (17) expiry date and (00) SSCC. The tool checks the identifiers, their value lengths and the GTIN check digit, inserts the FNC1 characters and draws the barcode as a PNG image or an SVG file with the data printed in human readable form.
Frequently asked questions
How do I write the data for GS1-128?
Write each application identifier in parentheses followed by its value, for example (01)09521234543213(17)261231(10)ABC123. The parentheses are not encoded; they tell the tool where each identifier starts. Spaces are removed before encoding.
Which application identifiers are supported?
All identifiers of the GS1 General Specifications, including (00) SSCC, (01) GTIN, (10) batch or lot, (11) production date, (17) expiry date, (21) serial number, (310n) net weight and (400) order number. Each value is checked for its required length and character set.
Does the tool check the GTIN check digit?
Yes. Check digits of GS1 keys such as the GTIN after (01) and the SSCC after (00) are verified, and a wrong one is refused with a message. Use the Barcode Check Digit Calculator to find the correct digit.
What is FNC1 and do I need to add it?
FNC1 is a special Code 128 character that marks the barcode as GS1 data and separates variable length fields. The tool inserts it at the start and after every variable length value that is not last, so you never type it.
What is the difference between GS1-128 and Code 128?
GS1-128 is Code 128 with a leading FNC1 and data structured by application identifiers, so receiving systems know which part is the GTIN, the batch or the expiry date. Plain Code 128 carries free text without that meaning.
Which format should I choose for the GS1-128 barcode?
SVG is a vector file that stays sharp at any size, which suits print artwork and design software. PNG is a raster image that works everywhere, including office documents and label printers. Both have a white background and a white margin around the symbol.
How long can a GS1-128 barcode be?
The GS1 specification limits a GS1-128 symbol to 48 data characters, not counting the parentheses. This tool accepts up to 200 characters of input and draws longer data too, but partners may reject it, so split long data over two barcodes as GS1 logistics labels do.
What do the scale and height controls do?
The scale from 1 to 10, default 3, multiplies the width of every bar and space. The default bar height is about 13 millimeters, and you can choose 5 to 50 millimeters. The human readable text with the identifiers in parentheses is printed below unless you turn it off.
Why is my data rejected?
Common reasons are an unknown identifier, a value that is too short or too long, letters where only digits are allowed, an invalid date, or characters outside the GS1 character set such as accented letters. The message names the kind of problem.
Is my data stored?
No. The data is used only to draw the barcode, and the image may be at most 4000 pixels on a side.