BarcodeOpsKit
BarcodeOpsKit

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Core operations are designed to run locally in your browser.

Local browser tool

GS1 Application Identifier parser

Inspect GS1 element-string fields, boundaries, formats and associations against a fixed local standards snapshot without sending the value to a server.

Processed locally in your browser.

Parsing uses the vendored GS1 Syntax Dictionary 2026-01-27 in this page. Input is not uploaded, resolved, stored, or placed in the URL.

Parse an element string

Paste bracketed data or scanner form. Use {GS}, a caret, or ASCII 29 for FNC1.

Maximum 4,096 characters and 100 AI fields. Leading zeroes are significant.

AI parsing evidence

Unknown or ambiguous boundaries are reported, never guessed.

Waiting for local input

Enter an element string and choose Parse locally.

How the parser works

Bracketed form names every field with parentheses. Scanner form omits the parentheses, so predefined-length fields are counted from the dictionary and variable fields use FNC1 (ASCII 29) when another field follows. The visible {GS} and caret forms are accepted as local entry aids.

Each field is checked for assigned AI, minimum and maximum length, numeric or GS1 character set, supported YYMMDD date structure, embedded Modulo-10 check digit, duplicates, required associations, and mutually exclusive combinations.

How to interpret the result

A valid field means its implemented syntax rules match snapshot2026-01-27. The separator column explains whether its boundary is fixed or requires FNC1 before a following field. Unknown and ambiguous boundaries are errors rather than guessed interpretations.

What this tool does not verify

Syntax validation does not establish GS1 issuance, company or registry ownership, product identity, a permitted business application, barcode image quality, physical print grade, certification, or retailer acceptance. Dictionary linter names not explicitly implemented by this stage are not presented as executed checks.

Worked examples

Fixed fields followed by a final lot

(01)09520123456788(17)301231(10)ABC123 provides a 14-digit GTIN, a six-digit date, and a final variable lot. No FNC1 is needed after the last field.

Variable field followed by a date

Scanner form 010952012345678810LOT-7{GS}17251231uses FNC1 after AI 10 so AI 17 has a deterministic boundary.

Missing-separator ambiguity

010952012345678810ABC17251231 could contain all those digits in the lot or a following AI 17 date. The parser reportsMISSING_SEPARATOR_AMBIGUOUS and does not choose.

TEST / SYNTHETIC / NOT FOR COMMERCIAL USE. Examples demonstrate parser behavior and do not claim assignment or ownership.

Common errors and recovery

Unknown AI
Check the parentheses or scanner offset against the assigned snapshot.
Missing separator
Add FNC1 after a variable field when another AI follows.
Required association missing
Add the required primary AI only if the source data actually contains it.
Check digit mismatch
Recheck the complete embedded identifier; it is never repaired silently.

Privacy and local processing

The string, parsed values and JSON stay in active page memory. They are not written to analytics, console logs, storage, URLs, requests, or external standards services. Copy and download occur only after the corresponding button is pressed and use value-free filenames.

Sources, version and review

Reviewed 2026-07-13 against the officialGS1 Barcode Syntax Dictionary 2026-01-27, licensed Apache-2.0, and GS1 General Specifications 26.0.0. BarcodeOpsKit is independent and not affiliated with GS1.

Build a GS1 Digital Link URI,scan a barcode locally, orreview the standards snapshot and maintenance policy. The guides toGS1 Application Identifiers and FNC1 separators explain the field boundaries in more detail.