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New: GS1-128 Application Identifier Mode Is Live in the Barcode Generator
A while back we wrote about the gap between plain Code 128 and true GS1-128 — and flagged full Application Identifier support as something we were evaluating. That gap is closed. The barcode generator now has a dedicated GS1-128 format with a visual AI builder, right in the tool. Here's what it does and how to use it.
Short answer: selecting GS1-128 from the format dropdown now opens an "Application Identifier builder" panel where you add AI fields by name — GTIN, batch/lot, expiry date, SSCC, and more — and the tool assembles a correct, scannable GS1-128 string for you.
Previously, getting a proper GS1-128 barcode out of a general tool meant typing the Application Identifier prefixes yourself — remembering that (01) means GTIN, (17) means expiry date, and getting the FNC1 start character and any variable-length separators right by hand. That's exactly the friction we called out as a limitation in an earlier post on this blog. The new GS1-128 format option removes it: the AI builder panel lists each identifier in plain language, you fill in the value, and the tool composes the AI-prefixed data string — including the FNC1 start character and separator characters where the standard requires them — automatically.
Where to find it: open the barcode generator, choose GS1-128 — Application Identifiers (shipping/logistics) from the format dropdown, and the "GS1-128 Application Identifier builder" panel appears above the appearance settings.
How the AI builder works, step by step
Short answer: add one row per Application Identifier, fill in each value, click "Build GS1-128 data," and the composed string fills the barcode data field and renders live.
The workflow inside the panel is short:
Add an AI row. Click "+ Add AI" to add a field — for example a GTIN, a batch/lot number, or an expiry date — for each piece of data your label needs to carry.
Fill in the values. Type the actual data for each Application Identifier you've added — no need to know the numeric AI code yourself, since the row is labeled in plain language.
Click "Build GS1-128 data." The tool composes the AI-prefixed string in the correct order and drops it into the barcode data field.
Check the live preview. The barcode renders instantly under the GS1-128 (Code 128-based) symbology, ready for the same PNG/SVG download options as every other format.
If you'd rather start from a known-good pattern than build one from an empty panel, two preset buttons are included: one fills in a shipping-carton example, the other a GTIN + batch + expiry example. Both are meant as a starting point to edit, not a final answer for your specific product — swap in your own GTIN, lot code, and dates before using the output for anything real.
A worked example: shipping carton
Short answer: a typical carton label needs a GTIN and often a batch/lot number and expiry date together — the AI builder turns three separate plain-language fields into one AI-structured string like (01)00614141123452(10)LOT4471(17)270601.
Take the same hypothetical scenario we used previously: a pallet or carton that needs to carry a product GTIN, a batch number for traceability, and a best-by date, all in one scan. Rather than typing that AI string by hand, you'd now add three rows in the builder — GTIN, batch/lot, expiry date — enter the sample values, and click build. The table below shows how the plain-language fields map to the AI-prefixed output.
Example AI builder rows and the resulting GS1-128 string (illustrative values)
Field (as shown in the builder)
Example value entered
AI prefix used
GTIN
00614141123452
(01)
Batch / lot number
LOT4471
(10)
Expiry date
270601 (YYMMDD)
(17)
The composed string above — (01)00614141123452(10)LOT4471(17)270601 — is illustrative only; it isn't a real product's GTIN. Substitute an actual GTIN issued through GS1 before printing a production label.
Build a GS1-128 barcode with the new Application Identifier picker:
Does the barcode generator now build real GS1-128 barcodes?
Yes. Selecting GS1-128 from the format list opens an Application Identifier builder where you add one or more AI fields — such as GTIN, batch/lot, or expiry date — and click Build GS1-128 data. The tool composes the correct AI-prefixed string (including the FNC1 start character and any required separators) and renders it as a Code 128-based GS1-128 barcode automatically.
Do I need to know the GS1 Application Identifier codes by heart to use this?
No. The GS1-128 panel shows each Application Identifier in plain language — GTIN, batch/lot number, expiry date, SSCC, and more — rather than expecting you to remember numeric codes like (01) or (17). You pick the field from the row, type the value, and the builder inserts the correct AI prefix for you.
Are there ready-made examples for common GS1-128 use cases?
Yes. The GS1-128 panel includes preset buttons for common patterns — a shipping carton example and a GTIN + batch + expiry example — that fill in a realistic set of rows in one click, so you can see a working structure before building your own from scratch.
Is the GS1-128 builder still entirely client-side, like the rest of the tool?
Yes. The Application Identifier values you enter, the composed GS1-128 string, and the rendered barcode are all generated in your browser. Nothing about the GS1-128 mode changes that — no field you type into the AI builder is sent to or logged by a server.
Does the GS1-128 mode replace plain Code 128 in the tool?
No, both remain available. Plain Code 128 (and Code 128-B/C) are still listed as separate format options for freeform strings with no Application Identifier structure. GS1-128 is an additional format option specifically for building AI-structured, GS1-compliant data — pick whichever matches your use case.
A note on this guide: the GTIN, batch/lot number, and expiry date values used in the worked example above are illustrative sample data, not a real product's registration. This article is for general informational purposes and isn't GS1 registration or supply-chain compliance advice — consult GS1 directly for authoritative Application Identifier specifications before using GS1-128 output in production.