GS1-128 — Barcode Format Guide & Generator
GS1-128 is a one-dimensional linear symbology in the Linear family. GS1 logistics barcode using bracketed AI markup, e.g. [01]…[3202]…. Typical homes for these codes are shipping labels, warehouse racks, membership cards, work orders and any place a cheap, universally readable 1D mark does the job.
- Category
- Linear
- Symbol
- Linear (1D) bars
- Data
- Mark application identifiers (AI) with square brackets
- Example
- [01]98898765432106[3202]012345[15]991231
Data format
Mark application identifiers (AI) with square brackets. Invalid payloads are rejected with the encoder’s own message, so mistakes surface before you print.
Strengths and limitations
Strengths
- Decodes on any ordinary 1D scanner — no special reader or app needed.
- Prints reliably with ordinary office printers on plain paper labels.
- Accepts structured GS1 application identifiers, so downstream systems parse the payload automatically.
Limitations
- Limited to a short payload — unsuitable for long strings.
- No error correction — a scratched or badly printed symbol fails outright.
- Payload must follow the GS1 AI syntax exactly; free-form input is rejected.
Generate one in QrDeco
- Open QrDeco and choose GS1-128 from the format list.
- Type or paste your data — for example [01]98898765432106[3202]012345[15]991231.
- Adjust size, colours, quiet zone or human-readable text in the style panel if you need them.
- Export an SVG or PDF for print, or a PNG for screens — generated locally in your browser, nothing is uploaded.
Scanning and printing tips
- Full-ASCII codes (Code 128, Extended Code 39) take mixed text; the 2-of-5 family encodes digits only — feeding letters to one of those is the classic encode error.
- Leave the quiet zones clear — blank space on both sides of the bars is part of the symbol.
- Print dark bars on a light background; red-only bars can vanish under red laser light.
- Keep the bars vertical to the scan direction and print at the symbol’s standard magnification.
- Verify one printed sample with a real scanner before committing to a full run.
Related formats
More from the Linear family, plus the family overview: