How to Create a Barcode Online for Products, Inventory, and Logistics

A barcode carries a value that a receiving system must understand. Before generating a symbol, decide what that value identifies and which reader will scan it. Drawing a valid-looking barcode does not allocate an identifier or create a product record in a stock system.

Choose a supported workflow

UDImaker generates Code 128, QR Code and GS1 DataMatrix. It can decode additional formats from images, but decoding support does not imply generation support. EAN-13, UPC-A, Code 39 and GS1-128 are not built-in generation options.

• Internal stock reference: Code 128 can carry a value such as DEMO-0042 when your receiving software expects that reference.
• Web address: QR Code can carry a full HTTPS URL for a manual or product page.
• Structured GS1 data: Use the GS1 DataMatrix fields for an assigned GTIN and supported production identifiers.
• Retail EAN/UPC: Obtain the correct assigned identifier and symbol from an appropriate source, then import its artwork if needed.

Create a Code 128 example

1. Open the Code 128 generator and continue to the editor.
2. Set your label dimensions, for example 70 × 35 mm for this exercise.
3. Select the Code 128 object and enter DEMO-0042 in its value field.
4. Keep the readable value visible and add “Internal sample” as separate text.
5. Leave clear space beside the bars and keep surrounding objects away from it.

Use the complete identifier, including leading zeros and separators required by your own system. A barcode contains the supplied value; it does not determine whether that value is unique in your inventory.

Check the receiving application

Decode an exported sample and compare the result character for character with DEMO-0042. Then scan a printed copy into the actual inventory field. Confirm that the application opens the intended item rather than treating the value as a quantity or an unknown product.

If the scanner adds a prefix, suffix or Enter key, document that configuration separately. It can change what the receiving software sees even when the encoded value is correct.

Export without changing proportions

SVG retains vector artwork; PDF places a 300 DPI raster image on a page with your chosen dimensions. Downloads require a verified account. Print at actual size with matching stock settings. If the code is too dense, shorten the business identifier where permitted or give the barcode more space instead of squeezing it horizontally.