Check the spec
Charset, lengths and check-digit rules for this symbology are listed above — the form enforces them instantly.
Free tools · Barcodes
Generate Code 39 Extended codes that scan.
Full-ASCII Code 39; lowercase and symbols survive exactly. Type the payload for Code 39 Extended below — validation, check digits and a local scan-test run in your browser before anything exports.
Barcode generator
Type text, get a symbol.
Runs locally in your browser. Nothing is uploaded; the field clears after ten idle minutes.
Advanced (GS1, checks, profiles, retail add-ons, supply-chain carrier)
This symbology has no tunable options — the engine picks the densest valid symbol.
Style (readable text, bar height, export size)
Bar height stretches bars vertically, which scanners ignore (only horizontal timing matters). The SVG download keeps the engine's exact geometry.
Specification
| Standards | ISO/IEC 16388 |
|---|---|
| Character set | Printable ASCII (A–Z, a–z, 0–9 and symbols), 1–40 characters. |
| Lengths | Hello-123! |
| Check digits | Shift-encoded full ASCII; no separate check digit. |
| Quiet zone | 10X quiet zone. |
| Capacity | Full printable ASCII, 1-40 characters here. |
Usage
Code 39 Extended labels industrial parts, documents and work orders: print it on badges, boards and bins where rugged 1D scanners operate.
- Code 39 Extended on asset tags for workshop tracking
- Code 39 Extended on work-order paperwork for line-side scanning
- Code 39 Extended proofs exported as PNG for quick sharing
Shape
Pros
- Code 39 Extended tolerates industrial printers, labels and badge stock.
- Case folding, padding and check rules are explained before encoding.
- PNG and SVG exports cover both quick sharing and print.
- The self-verify readout shows exactly what a scanner will observe.
Cons
- Code 39 Extended is wider per character than 2D codes for long payloads.
- Dense narrow bars demand close, steady photography when verifying.
- Damaged or smudged labels lose characters with no error correction.
- Colored or low-contrast prints scan poorly.
Form requirements
- Enter Hello-123!.
- Printable ASCII (A–Z, a–z, 0–9 and symbols), 1–40 characters.
- The symbol is decoded again locally before preview and downloads unlock.
Sources
- ISO/IEC 16388 (ISO)
- AIM symbology specifications (AIM)
Related formats
Keep exploring.
How it works
Three steps, all on your device.
The same engine that reads barcodes writes them — every symbol is decoded again before you see it.
Type the payload
Every symbol is validated and decoded again on your device before it is shown.
Download and print
Take a resolution-independent SVG for print or a PNG for sharing. Nothing is uploaded.
Questions
Code 39 Extended Generator & Specs, answered.
If you manage servers by hand, see the engineering services behind this tools series.
What can I type for Code 39 Extended?
Printable ASCII (A–Z, a–z, 0–9 and symbols), 1–40 characters. Example: Hello-123!.
How does Code 39 Extended handle check digits and printing?
Shift-encoded full ASCII; no separate check digit. 10X quiet zone. Export SVG for print and PNG for sharing; both render on your device.
Is my data uploaded anywhere?
No. Encoding and verification run entirely in your browser — the page makes no network requests with your data, stores nothing, and wipes the field after ten idle minutes.
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