Extended Code 39 — Barcode Format Guide & Generator
Extended Code 39 is a one-dimensional linear symbology in the Linear family. Code 39 extended to full 7-bit ASCII. 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
- Plain text within the symbology’s character set and length limits
- Example
- 123.45#@fd
Data format
Enter the payload as plain text. The encoder enforces each symbology’s character set and length rules, and rejects out-of-spec input with a clear message instead of silently producing a bad symbol.
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.
Limitations
- Limited to a short payload — unsuitable for long strings.
- No error correction — a scratched or badly printed symbol fails outright.
Generate one in QrDeco
- Open QrDeco and choose Extended Code 39 from the format list.
- Type or paste your data — for example 123.45#@fd.
- 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.
Options
- Check digit: None · Add & show · Add, hidden
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: