Developer tool
Barcode Generator
Generate retail and logistics barcodes with valid check digits and quiet zones, then download a crisp SVG or a high-resolution PNG.
How it works
Choose a format: EAN-13, EAN-8, UPC-A, Code 39 or Code 128.
Enter the value. A missing EAN or UPC check digit is calculated; a supplied one is validated.
Generate the barcode and review the preview, including the white quiet zone around the bars.
Download SVG for print or design work, or PNG for a raster image.
Frequently asked questions
Which barcode formats are supported?
EAN-13, EAN-8, UPC-A, Code 39 and Code 128. QR codes and other two-dimensional formats are not part of this tool; use the separate QR generator for those.
What happens if I leave out the check digit?
For EAN-13, EAN-8 and UPC-A, a missing check digit is calculated for you. If you provide one, it is validated against the value. Code 39 can also include an optional mod-43 check character; Code 128 uses its own checksum internally.
Will the barcode scan?
The output follows the selected format, but it has not been verified with a physical scanner or a print proof. Scan the downloaded file with the device and scanner you plan to use, keep the quiet zone intact, and print at a sufficient size and contrast for the reader.
Can I make a sheet of labels or a batch of codes?
Not in this version. It generates one code at a time and does not provide label sheets, batch input or print sizing. Generate each code separately and place it in your label or design software.
What is the quiet zone?
The quiet zone is the blank margin on each side of the bars. Scanners need it to find where the barcode starts and ends. The exported image includes a quiet zone; do not crop it away when placing the code on a label or page.
Is my barcode data uploaded?
No. The barcode is generated in your browser from the value you enter. Ontool does not receive the data, and there is no account or saved history.