Create a Code 128 barcode from text or numbers and download the SVG.
Generated locally in your browser.
How do you generate a Code 128 barcode?
Code 128 (subset B) encodes printable ASCII, prepends a start symbol, appends a mod-103 checksum and a stop symbol, then renders each value as its bar/space pattern. For example, the text TOOLZIO-123 becomes a Code 128 barcode with a built-in checksum so scanners can verify it. It downloads as a crisp, scalable SVG.
Understanding your result
Code 128 is a high-density linear barcode used widely in shipping and packaging. The checksum lets scanners detect misreads.
Formula and method
Code 128 (subset B) encodes printable ASCII, prepends a start symbol, appends a mod-103 checksum and a stop symbol, then renders each value as its bar/space pattern.
Assumptions and limitations
This tool produces Code 128 subset B only, which covers standard printable ASCII characters; it does not create retail formats such as EAN, UPC or QR codes. Reliable scanning still depends on adequate size, contrast and a quiet zone, so test the printed barcode with your scanner before a full run.
Worked example
The text TOOLZIO-123 becomes a Code 128 barcode with a built-in checksum so scanners can verify it.
How to use this tool
- Type the text or number to encode.
- Set the bar height and whether to show the caption.
- Download the SVG and print it.
Common mistakes to avoid
- Printing too small — keep enough quiet space (margin) on each side so scanners can read it.
- Using non-standard characters; subset B covers letters, digits and common symbols.
About the Barcode Generator
Turn any text or number into a scannable Code 128 barcode and download it as a sharp, scalable SVG. Everything is generated in your browser.
Who should use this tool
Small shops, warehouses and makers labelling products, assets or inventory.
Benefits
- Adds a mod-103 checksum so scanners can detect misreads automatically.
- Exports a scalable SVG that stays sharp at any print size.
- Encodes letters, numbers and symbols using the high-density Code 128 standard.
- Generates everything in your browser, so your data is never uploaded.
Practical use cases
- Labelling parcels and packaging for shipping.
- Creating internal asset or inventory tags.
- Producing scannable reference codes for warehouse locations.
- Adding a machine-readable serial or batch number to a document.
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Frequently asked questions
Which barcode type is this?
Code 128 (subset B), a compact, widely supported standard for letters, digits and symbols.
Is the SVG scalable?
Yes. SVG is vector, so it stays crisp at any print size. We recommend a quick scan test before a large print run.
What characters can a Code 128 barcode contain?
This generator uses Code 128 subset B, which encodes standard printable ASCII: uppercase and lowercase letters, digits and common punctuation. That makes it well suited to mixed alphanumeric references such as order or asset codes. The checksum is added automatically so scanners can verify the result.