Code128B Generator — true Set B encoding

Code128B is the code set of the Code 128 barcode symbology that covers everyday text: uppercase and lowercase letters, digits, spaces and the printable punctuation marks on a standard keyboard. When people say a value "needs full text" in a Code 128 barcode, Code128B is usually the answer.

A Code128B symbol starts with a Start-B pattern, encodes each character as one bar/space module pair, and ends with a mandatory check character and stop pattern. The check character is calculated from the value itself, which is why scanners catch a mis-typed character in a Set B label so reliably.

This generator always emits true Set B encoding. It does not silently fall back to another code set, and it rejects characters outside Set B — such as tab or other control characters — instead of deleting them behind your back. What you scan is always exactly what you typed.

Code128B is the default choice whenever the value mixes letters with digits or includes punctuation: product SKUs like ABC-12345, order references like ORDER-2026/B, or location codes like Aisle 4-B. If your values contain lowercase letters, Set B is the only Code 128 set that carries them without switching, which is why a Code128B generator is the workhorse for mixed alphanumeric data.

For values that are nothing but a long run of digits, Code 128C produces a visibly narrower symbol because it packs two digits into the space of one character — use the Code128C Generator for those. Choosing between them deliberately, instead of letting an auto encoder guess, keeps every Code128B symbol predictable for downstream systems.

Code128B covers printable ASCII from space (32) through tilde ~ (126): the digits 0–9, the letters a–z and A–Z, the space character, and punctuation such as - . / + ( ) : % # $ @ & * = ? ! and quotes. That is 95 characters in total — everything a standard keyboard can type without a control key.

Characters outside that range — control characters like tab, or characters from non-Latin alphabets — cannot be encoded in Set B. The Code128B generator rejects them with a specific message rather than stripping or substituting them, so the barcode you print matches the value in your system character for character.

A Code128B barcode is only as good as its print. Keep the quiet zone — the clear white margin around the bars — intact after cutting, match the bar width to your printer’s resolution, and always scan a sample with the actual device that will read the label in production. The SVG output is vector, so it scales to any label size without the blur that corrupts bar edges.