Code 128 and GS1-128
Code 128 is a barcode that can hold any letter, digit or keyboard symbol, so it turns up on shipping and warehouse labels. GS1-128 is the GS1 version, where each piece of data starts with an Application Identifier printed in brackets.
Easily confused with
- ITF-14 (carton barcode)ITF-14 is the barcode printed on cardboard cartons and cases. Its 14 digits identify a box of a product, not a single item: the first digit says which packing level it is, and the rest is the item’s own product number with a new check digit.
- Code 39Two bar widths only, with asterisks in its printed text.
How to read it
Keyence’s guide dates Code 128 to 1981, at Computer Identics Corporation in the US, and says it can encode all 128 ASCII characters: digits, upper and lower case letters, punctuation and control codes. Each character is three bars and three spaces, in four widths. One of three start characters picks the character set: A, B, or C, which packs two digits into each character, making long numbers compact. The standard is ISO/IEC 15417.
Also searched as: application identifier barcode, code 128, code128, ean-128, gs1-128, shipping label barcode, ucc-128.
These pages say what each code and its parts mean under the standard that defines it. A barcode identifies an item; it doesn’t say where the item was made or whether it is genuine, and the label and the maker are the place to look for that.
GS1-128 and the numbers in brackets
GS1-128 is a subset of Code 128 that only GS1 may use, marked by a special character, FNC1, after the start character. Its data is a string of element strings, each led by a GS1 Application Identifier: (01) is the 14-digit product number, and others carry a date, a lot number, a weight or a destination. Keyence notes that the brackets are printed for people to read and aren’t in the barcode itself.
Look-alikes
A Code 39 barcode has only two bar widths and wider spaces between characters, and its text often begins and ends with an asterisk. An ITF-14 holds digits only and usually sits in a thick frame.
Read next
- Next in Barcodes and QR codesCode 39Code 39 is an older barcode for letters and numbers, used on car parts labels and US military shipping labels. Its text is often printed between two asterisks, which mark the start and end of the code.
- The same shape in Smoke and CO alarm soundsLow-frequency 520 Hz alarm (sleeping rooms)A fire alarm in a sleeping room that sounds a low buzz in place of a high-pitched beep. It is the three-beep fire alarm rhythm at 520 Hz, which NFPA 72 requires of alarms provided to wake people in sleeping areas.
More barcodes and QR codes
The same shape elsewhere
Browse symbols drawn with letters and numbers or lines.
Sources
- CODE 128 and GS1-128 | Basics of Barcodes, Barcode Information & Tips, KEYENCE Corporation, CODE 128; GS1-128
- GS1 General Specifications Standard, Release 26.0, ratified January 2026, GS1 AISBL, §5.1.1; §5.1.2
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research
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