Code 128 barcode generator

Code 128 is a linear barcode: a row of bars and spaces read from side to side. It gets its name from the 128 characters it can carry, which cover everything on an English keyboard.

Characters

All 128 ASCII characters: capital and small letters, digits, spaces and punctuation

Length

No fixed length. Each character adds width, so short values make the best labels

Check character

Always included, calculated for you. Scanners check it, so a misread is rejected instead of typed in

Long numbers

Packed two digits at a time, so a 12-digit number makes a shorter barcode than 12 letters would

Scanners

Every linear (1D) and 2D barcode scanner, and phone apps

Standard

ISO/IEC 15417

Code 128 suits any label where you choose the numbering yourself:

• Job cards and work orders. Scan the job number at each station to record where a job is.

• Bins, racks and stock locations. A short location code, such as A-12-03, scans faster than reading it out.

• Raw material lots and heat numbers. So you can tell which lot went into which job when a customer asks.

• Serial numbers on finished goods. Use “Number a run” in the generator, or the bulk barcode generator, to make hundreds in order.

• Internal part numbers and drawings. Part numbers usually mix letters, digits and dashes, which Code 128 handles.

For products sold in shops or on marketplaces, use an EAN-13 barcode with GS1 numbers instead.

Both are linear barcodes, and most scanners read both. Code 128 is the better choice unless a customer or an older system asks for Code 39.

More on the older code on the Code 39 barcode generator.

GS1-128 is Code 128 with a special start character and data written in GS1's format: each piece of data sits behind a code in brackets, such as (01) for the product number, (10) for the batch and (17) for the expiry date. Scanners and buyers' systems can then split the label into its fields.

Use plain Code 128 for your own labels. Use GS1-128 when a customer's label specification asks for it, usually on cartons and pallets. It's in the generator's list of code types, and it needs a product number issued to your company by GS1.

• Leave the margins. Code 128 needs a blank margin of at least ten narrow-bar widths on each side. The generator adds it; don't crop it off when you place the code on a label.

• Shorten the value, not the bars. If the code is too wide for the label, use a shorter value or a wider label. Squeezing the bars below what your printer can print cleanly is the most common reason a Code 128 label won't scan.

• Keep it tall enough. Short, wide codes are hard to scan by hand. On a small label, give the bars at least a third of the label's height.

• Print the text under it. So people can still read the value when there's no scanner around.

• Test it where it lives. Print a few, stick them on the bin or part, and scan them again after a few days.

Excel can't draw a Code 128 barcode with a font alone. A Code 128 font needs a formula or an add-in that calculates the check character for every cell, or the codes won't scan.

The quicker way: copy the column from Excel, paste it into the generator above under “Many labels”, and print the labels or download all the codes as images. A second column prints above each code as label text. Our guide on how to generate barcodes for your shop floor covers Excel, Word mail merge and printers in more detail.