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GS1-128

Free GS1-128 Generator

GS1 AI (01) · (10) · (17) · (21) … · FNC1: automatic

Live generationNot sent to serverMobile & PDA optimized

GS1-128

Free GS1-128 Generator

Input is processed only on this device
Barcode formatGS1-128
Input rulesGS1 AI (01) · (10) · (17) · (21) … · FNC1: automatic
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The barcode has been adjusted to the screen size.

1GS1-128
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Scan a barcode from an image or camera. Processing stays on this device.

GS1-128: structured supply-chain data

Application Identifiers describe each field

GS1-128 is Code 128 with an initial FNC1 and GS1 Application Identifiers (AIs). For example, (01) carries a 14-digit GTIN, (17) an expiry date in YYMMDD, (10) a batch/lot and (21) a serial number. Parentheses are human-readable notation, not literal data encoded into the bars.

Why FNC1 separators matter

Some AIs have a predefined data length; others have variable length. If a variable-length field is followed by another field, an FNC1 separator must be encoded so scanners know where the field ends. BarcodeOn inserts separators for supported AI combinations.

Check the complete logistics workflow

Validate the GTIN check digit, date fields and supported character set. GS1-128 symbols are subject to symbol length, quiet-zone and application-specific print requirements. Scan the physical label with the target warehouse system; a correctly decoded symbol is not itself a GS1 compliance certificate.

GS1-128 application identifiers and FNC1

Common application identifiers

AI (01) identifies a 14-digit GTIN, AI (17) is an expiry date in YYMMDD format, AI (10) carries a batch or lot, and AI (21) carries a serial number. Data formats and allowed combinations must follow the current GS1 specifications.

Why FNC1 matters

GS1-128 requires an FNC1 character after the start pattern. Variable-length fields such as lot and serial need an FNC1 separator when another AI follows, except when the field is last. Parentheses are human-readable AI notation and are not encoded as data characters.

Validate before production

Check GTIN check digits, date semantics, field lengths and scanner interpretation. A barcode image that looks correct is not proof that the full GS1 element string is valid.

Official GS1 identifiers

BarcodeOn does not issue company prefixes or official GTINs. Obtain allocated identifiers through GS1 and confirm trading-partner requirements before using labels commercially.

Frequently asked questions

Is ordinary Code 128 interchangeable with GS1-128?

No. GS1-128 requires an initial FNC1 and valid GS1 AI structure; ordinary Code 128 does not convey that standardised structure.

Are the parentheses encoded?

No. The parentheses in (01), (10) and similar strings are readable field markers, not data characters in the symbol.

Can the builder issue a new GTIN?

No. The builder validates and encodes identifiers supplied by the user; it does not allocate official GS1 numbers.

Independent general-purpose tool

Whether a generated barcode can be used at work depends on your workplace rules and scanner settings.