What are they?
A Data Matrix code is a two-dimensional barcode made of black and white square modules arranged in a grid. It is used to mark small parts, medical packaging and industrial components where a linear barcode would not fit. Each code you generate here can hold up to 1,550 characters — comfortably covering typical use cases like part marking and small package labels. (The Data Matrix format itself supports up to ~2,335 alphanumeric characters; this tool's limit exists to keep generation fast and files manageable.)
How do I read Data Matrix codes?
Readers configured for the Data Matrix symbology can read them: dedicated 2D imagers, most barcode-scanning apps, and, on Android, apps built with Google's ML Kit. Reading also depends on size, focus and configuration — ML Kit specifically expects the code near the center of the frame and only decodes one Data Matrix per image. Some built-in phone camera apps recognize Data Matrix too, though many are tuned mainly for QR codes. The code can be read from any orientation, and its error correction lets it be decoded even when part of the printed surface is damaged.
Is this tool free?
Yes. There is no account required, and the PNG images have no watermark; the PDF export adds a small "Created with" line in the page header. You can generate up to 500 codes per submission.
What can I do with a generated code?
Download a single code as a PNG, open it in a new tab on its own page, or copy its permalink to share the exact code with someone else. Download as ZIP gives you every code as a PNG image; download as PDF gives you a printable document with all your codes and their text.
What is ECC 200 and the quiet zone?
ECC 200 is the current version of the Data Matrix symbology defined by ISO/IEC 16022, and the one this generator produces. It uses Reed-Solomon error correction, and the standard requires a quiet zone: a blank border around the symbol, at least the width of 1 module on every side. A module is one square of the grid, so the margin scales with the code. A larger margin, 2 to 4 modules, is recommended for more reliable reads in noisy or reflective environments, but it is not required. When codes are printed close together on a sheet, a quiet zone under the minimum can prevent a scanner from detecting or reliably decoding the symbol next to it, which is why the generator warns below 1. The millimeter figure shown next to the quiet zone control assumes the code is printed at 0.5 mm per module; if you print larger or smaller, the physical margin scales with the code.
