Labeling a batch of parts, a run of serial numbers or a shelf of inventory means making many Data Matrix codes, not one. Doing that one code at a time is slow and easy to get wrong. This guide covers how to generate a whole list at once with the online generator, what to check in your list before you start, and how to choose between the PDF and ZIP exports.
Prepare your list
The generator makes one code for every line of text you enter. If your data is a column in a spreadsheet, copy the column and paste it into the text box: each cell becomes one line, and so one code. A few rules apply to the text itself:
- One code per line. A line break starts the next code, so do not put line breaks inside a value.
- ASCII text only. Plain letters, digits and common punctuation work. The generator is built for ASCII, so accented letters and other alphabets are not supported.
- Up to 500 codes per submission. For a longer list, split it into batches of 500 or fewer and generate each batch in turn.
- Each code can hold up to 1,550 characters, far more than a serial number or part number needs.
Avoid the spreadsheet traps
Most problems with bulk lists come from the spreadsheet, not from the generator. Two to check before you paste:
- Leading zeros. A spreadsheet often treats 000123 as the number 123 and drops the zeros. Format the column as text before you enter or import the values, then copy it.
- Trailing spaces and blank rows. A stray space at the end of a value ends up inside the code, and empty rows can add lines you did not intend. Clear empty rows and trim values first.
After you paste, use the preview to compare the first and the last few codes against your source before you export.
Choose the export: PDF or ZIP
- PDF gives you a printable document with all your codes and their text. Use it when you want to print the whole batch directly.
- ZIP gives you every code as its own PNG image. Use it when the codes go into a label design tool, a template or another system that places images one by one.
The PNG images have no watermark. The PDF adds a small line in the page header. You can also download a single code as a PNG from the preview, or open it on its own page.
Check before you print the whole batch
- Scan a few first. Print a handful of codes at the real size and scan them with the reader you will use in production. It is a lot cheaper to find a problem on five labels than on five hundred.
- Keep the quiet zone. The blank border around each code should be at least one module wide, the minimum in ISO/IEC 16022. The generator warns you if you go below it, which matters most when codes are printed side by side.
- Keep strong contrast. Dark modules on a light background read most reliably. If you change the colors, check that the contrast stays high.
If a code does not scan, How to Read Datamatrix Codes lists what to check on the reader side. For background on the format, see the Data Matrix guide.
