I have printed a Code 128 barcode but my scanner doesn't read or scan it

This can have several reasons:
  • Make sure that the code symbology Code 128 is actually activated in the barcode scanner. Consult your scanner's manual.
  • The print quality must be adequate. For Code 128, a resolution of 150-200dpi or higher is recommended. Also, make sure that the code is not printed too small. The minimum module width (i.e. the width of the narrowest bar) should not be below 0.3 mm. The height should not be below 10 mm. A space (the so called "quiet zone") of at least five to ten millimeters should be left around the code.
  • By default, many scanners require a barcode to encode at least four characters. If so, a barcode with only three characters will not scan. Check your barcode scanner's manual.
  • With Code 128 almost all barcode readers on the market today will will expect a checksum with the barcode. If the code does not scan you may have created it without a checksum.
  • Finally, when using a so called barcode font, you might have to add start and stop symbols to the data. When using a barcode font in office applications like Word or Excel, you can't just simply select the data and change the font. Code 128 is a very advanced barcode type which requires preparing your data for use with a font. Usually a macro, add-in, or stand-alone app will be supplied with the font that handles all necessary steps. An example is our barcode add-in for Excel.
Use the following verified sample barcode to test the settings of your scanner. It encodes nine characters, has the required start/stop symbols, the proper checksum, and sufficient quality.

Code 128 - sample barcode to test barcode scanner

Right-click and "Save as..." to print the barcode out. A good CCD scanner or imager will also be able to scan the code directly from the screen.

For more sample 128 barcodes and a general introduction to Code 128, see our page Code 128 explained.

Creating compliant Code 128 barcodes

For the creation of compliant, working barcodes like the one above, see Softmatic BarcodePlus. This software is very easy to use. Simply select "Code 128", enter your data and the code is created right away:

The software is available for Mac and PC.

For bulk creation of Code 128 and other linear and 2D symbologies, see our Bulk Barcode Generator (Video).