RunToolRunBarcode Generator
Generate barcodes.
How to Generate a Barcode
Enter the value
Type the number or text to encode — a product code, SKU or ID.
Pick the barcode format
Choose CODE128, EAN-13 or another symbology to match your use.
Download the image
Save a crisp barcode ready for labels, packaging or documents.
Different barcodes encode different things
The symbologies are not interchangeable. EAN-13 and UPC encode a fixed-length product number and nothing else. Code 128 encodes arbitrary text of variable length. Code 39 is older, less dense and still common in industrial settings. ITF-14 is for shipping cartons.
Choosing the wrong one produces a barcode that scans correctly and means nothing to the system reading it. The symbology is part of the message: a scanner reading EAN-13 expects a product identifier and will treat the digits accordingly.
Retail barcodes have to be registered
A generator can produce a valid-looking EAN-13 from any thirteen digits, and that barcode will scan. It will not identify your product to anyone, because retail numbers are allocated by GS1 and a number you invented belongs to someone else or to nobody.
Selling through retailers or major marketplaces requires a properly allocated number. Generating one yourself is fine for internal inventory, asset tracking and warehouse use, where you control both the numbering and the systems that read it.
Check digits
EAN, UPC and several other symbologies end with a check digit calculated from the preceding numbers. It exists so a scanner can detect a misread: if the digits do not produce the stated check digit, the read is rejected rather than passed on wrongly.
This is why entering twelve digits and expecting to choose the thirteenth does not work — the last digit is determined by the others. If a barcode consistently fails to scan and the bars look fine, an incorrect check digit is the most common explanation.
Size, quiet zones and print quality
Every barcode needs clear space either side — the quiet zone — and scanners fail without it far more often than for any other reason. A barcode printed hard against a box edge or a block of text is the classic unscannable label.
Physical size matters too. Each symbology has a nominal size, and printing much below it makes the narrowest bars thinner than the printer can render cleanly. Barcodes should be printed at their intended size on a good printer, never scaled down to fit a space or photographed and reprinted.
Contrast, orientation and testing
Scanners read contrast between bars and background. Black on white is ideal; dark blue on white works; red bars are effectively invisible to older red-laser scanners, which see them as background. Printing on transparent or reflective surfaces causes similar failures.
Test with the actual scanner in the actual conditions before printing thousands. Generation happens in your browser, so internal product codes and inventory numbers are not transmitted anywhere.