Go to the Barcoding Free Barcode Generator website (see References).
Enter your 13-digit ISBN code (without spaces) into the "Barcode Data" box.
Click "Generate Barcode."
Right-click the created barcode and click "Save Image As" (the exact wording may vary depending on your browser) to save the barcode to your computer.
Go to the Online Barcode Generator website (see References).
Click the "Symbology" drop-down menu and choose the type of barcode you want. Typically, ISBNs use "EAN-13" barcode types.
Enter your 13-digit ISBN in the "Contents" box.
Click "Make Barcode" to create your barcode.
Right-click the "EPS," "BMP," "JPEG," "PNG" or "TIFF" links and click "Save Link As" (the exact wording may vary depending on your browser). Choose a download location and click "Save" to save your generated barcode to your computer.
Go to the Free On-Line Linear Barcode Image Creator website (see References).
Enter the 13-digit ISBN in the "Data to Encode" box.
Click the "Barcode Symbology" drop-down menu and select "EAN-13."
Click "Update Barcode" or "Generate in New Window."
Right-click the created barcode and click "Save Image As" (the exact wording may vary depending on your browser) to save the barcode to your computer.