Data Matrix Generator: Free Data Matrix Codes Online

What is a Data Matrix code?

A Data Matrix is a two-dimensional barcode made of square modules inside a solid “L” finder pattern on two sides and an alternating timing pattern on the other two. It is used where space is tight: small parts, electronic components, pharmaceutical packs, medical devices and logistics labels. The version in use today is ECC 200, standardised in ISO/IEC 16022.

This generator makes ECC 200 symbols in all 24 square sizes, from 10 × 10 to 144 × 144 modules, and the 6 rectangular sizes from 8 × 18 to 16 × 48. For product codes that follow GS1 rules (GTIN, expiry date, batch, serial), use the GS1 Data Matrix generator, which adds FNC1 and checks every Application Identifier.

How much data fits in a Data Matrix?

Capacity depends on the symbol size and on the kind of data: digits pack two to a codeword, so a symbol holds about twice as many digits as letters. Error correction is fixed per size; you do not pick a level as you do with QR codes. The table shows a few sizes from the GS1 General Specifications (Table 5-32, equivalent to Table 7 of ISO/IEC 16022).

The largest square symbol holds 3,116 digits, 2,335 alphanumeric characters or 1,556 bytes. The largest rectangle (16x48) holds 98 digits. Pick Auto and the tool chooses the smallest size that fits; pick a size yourself when every label in a run must look the same.

How to make a Data Matrix code

Four steps, no account:

1. Type or paste the text, number or URL into the box. Latin letters, digits and punctuation work everywhere; other scripts are stored as UTF-8 with an ECI marker.
2. Choose square or rectangle, and Auto or a fixed size.
3. Set the module size in pixels, the quiet zone in modules and the two colours. The preview updates as you type.
4. Click Download PNG for documents and screens, or Download SVG for print and label software, where it scales without blur.

Quiet zone, module size and colours: which settings matter?

The quiet zone is the clear margin around the code. GS1 specifies a quiet zone one module wide on all four sides of a GS1 DataMatrix; QR Code needs four modules (GS1 General Specifications, Table 5-46). The tool defaults to 2 modules to leave room for trimming; do not go below 1 and do not print anything inside it.

The module size is the side of one square. On screen it is set in pixels here. In print it is called the X-dimension: for GS1 DataMatrix on retail consumer packaging GS1 gives a minimum of 0.396 mm, a target of 0.495 mm and a maximum of 0.990 mm (Table 5-46). For export to print, use SVG and scale it so each module lands in that range.

Colours: dark modules on a light background are the safe choice. The tool warns when the contrast between your two colours is low, or when the code is lighter than its background.

Source: GS1 General Specifications, Release 26.0, section 5.6.

What is free and what does Pro add?

Single codes stay free with every option. Data Matrix Generator Pro is for long lists: US$19.90, paid once.

Details and refunds are on the pricing page.

Many codes at once: batches and label sheets

Open Batch under the tool, paste one value per line or load a CSV file, and download a ZIP of PNG or SVG files, or a PDF laid out for Avery 5160, 5163 or 5167 label sheets. Up to 5 codes per export are free. The Data Matrix labels page explains label sizes and printing.

When does a Data Matrix code not scan?

Most failures come from the print, not the data:

• The quiet zone is cut off or printed over by text or a border.
• The modules are too small for the printer or the scanner: at small sizes, use a larger module or a rectangle with fewer rows.
• Low contrast, glossy film or a code printed light on dark for a scanner that only reads dark on light.
• The label was printed with “Fit to page”, which shrinks every module. Print PDFs at 100%.
• Older laser scanners: a Data Matrix needs a camera-based (imaging) scanner or a phone.

Data Matrix or QR code?

Both are 2D codes. A Data Matrix is more compact for short data and needs a smaller quiet zone (1 module against 4 for QR Code in GS1’s Table 5-46), which is why it is common on small parts and healthcare packs. QR Code lets you choose the error correction level and is what most people expect for links on posters. If a regulation or a trading partner asks for GS1 DataMatrix, use the GS1 mode; for marketing links, a QR code is usually the better choice.