How to Disable Default Two-Sided Duplex Printing on Mac via CUPS

Some printers (and their drivers) default to two-sided printing, which many people do not prefer as the default option. Luckily, this can easily be disabled via the CUPS web interface. There are probably other ways to accomplish this, too, but I found this to be quick and painless. At the time of this post, this is tested and working on Mac OS 10.16 Big Sur.

1. Open Terminal (in Applications->Utilities) and enter: cupsctl WebInterface=yes

2. Open your browser and enter the following URL: http://localhost:631/printers/

3. Click on the printer you would like to configure. In “Set default options”, under the “General” tab, set the “Duplex” option to “Off”. Be sure to click the “Set Default Options” button at the bottom of the page to save the settings.

• If you don't see the duplex option listed exactly as described above, the duplex option may be in a slightly different spot. I advise clicking around to see if you can find it. It can vary by printer model.

4. When prompted for a username and password, you must enter the account name and password of any admin account on your computer. That is, the same username and password used to log on to the computer (again, assuming the account is an admin). If you are an admin and you're not sure of your username or want to confirm it, go back to Terminal and enter the following command: whoami

5. Optional -- Disable web access to CUPS: Open Terminal (in Applications->Utilities) and enter: cupsctl WebInterface=no