GS1 AI parser

GUIDE

What this tool does

The GS1 Application Identifier Parser decodes element strings containing numeric Application Identifiers that prefix data fields in GS1 barcodes and RFID tags. It interprets parenthesized syntax such as (01)09506000134352(17)271231(10)LOT-2048(21)SN00042, FNC1 or ASCII 29 separated sequences, and raw scanner streams. Fixed-length AIs consume their exact character count while variable-length fields terminate at the group separator. Supply chain analysts, warehouse software developers, and label printers rely on this parser to validate encoded product, date, lot, and serial information without external dependencies. Browser-local execution keeps all input strings private during analysis of production or test data. The parser supports the most frequently used identifiers from the GS1 General Specifications, including those for GTINs, serial shipping container codes, batch numbers, expiration dates, and serial numbers. It distinguishes between fixed-length numeric fields and variable-length alphanumeric fields by consulting an internal reference of AI lengths and data types. This approach allows accurate segmentation even when separators are omitted after fixed-length values.

Worked example with realistic numbers

Consider the input (01)09506000134352(17)271231(10)LOT-2048(21)SN00042. The parser identifies AI 01 as a 14-digit GTIN consuming the next fourteen characters after the identifier. AI 17 follows as a six-digit expiration date. AI 10 captures the variable lot until the next AI or separator. AI 21 extracts the serial number. A table of results shows each AI, its meaning, extracted value, and length consumed.

Second worked example

A second input string (00)123456789012345678(10)ABC123(17)250630 demonstrates handling of an 18-digit SSCC followed by a variable batch and a six-digit date. The parser consumes the full 18 characters after AI 00, then treats AI 10 as variable until the next identifier and extracts the expiration date from AI 17.

Formula and method table

Units and conversions notes

Dates appear in YYMMDD format and require conversion to full calendar dates using a 2000 base year for most modern strings. GTIN values remain numeric strings without check-digit recalculation by this parser. Lot and serial fields preserve original alphanumeric characters including hyphens. Length units are always characters; no metric conversions apply. When an AI 90 or higher appears the parser flags it as potentially sector-specific and leaves the value intact for manual review.

Limitations

The parser recognizes only the most common AIs listed in the GS1 General Specifications. Rare or newly introduced identifiers trigger an unknown flag and stop further processing. It does not validate check digits on GTINs or convert Julian dates. Extremely long element strings exceeding typical scanner buffers may truncate before the final separator. No support exists for binary or compressed GS1 formats used in certain EPC schemes. The tool cannot interpret concatenated AIs that violate length rules or handle encrypted payloads. Sector-specific extensions beyond AI 90 require external lookup tables not included in the parser.

Common mistakes

• Omitting the group separator after a variable-length field causes the next AI to be misinterpreted as data.
• Entering a six-digit date without confirming YYMMDD order leads to incorrect expiration interpretation.
• Treating parenthesized input as raw scanner output wastes the explicit boundary information the parser can exploit.
• Ignoring the unknown-AI flag on sector-specific codes such as AI 95 may hide critical traceability data required by regulations.
• Assuming all AIs are fixed length results in premature termination of variable fields like lot numbers.
• Supplying input containing non-GS1 prefixes without stripping them first produces offset errors in value extraction.
• Overlooking that AI 00 requires exactly 18 digits after the identifier leads to incomplete SSCC parsing.