OKI B721dn: Setup, Drivers, Ink and Common Problems

Is the OKI B721dn right for you?

The B721dn is a 47 ppm heavy-duty mono printer designed for continuous departmental printing, with a 25,000-page toner and a metal-reinforced paper path. Offices that print statements, picking lists or legal bundles all day chose these over lighter desktop machines. Second-hand units are usually cheap, but check the fuser count — the fuser is a wear item on high-mileage machines and is not included with the toner.

Best for: Offices printing continuously all day at high mono volume

Setting up the OKI B721dn

Add it as a Standard TCP/IP printer with OKI's PCL6 driver, and set the correct tray configuration so applications can select the right stock. Consider the OKI LPR Utility if the printer must be tracked across changing IP addresses. If the printer slows to half speed on certain jobs, the paper type is likely set to a heavy media weight that forces a lower fuser speed.

1. Unbox and prepare. Remove every piece of shipping tape and packing material, install the ink cartridges, and load paper in the tray.
2. Join your Wi-Fi. Keep the printer close to the router for setup. Most printers only connect to the 2.4GHz band, so if your router broadcasts one merged network name you may need to split the bands temporarily. See our Wi-Fi guide if it will not join.
3. Install the setup app. Use OKI's official app rather than a driver you found on a search result — third-party driver sites are the most common source of printer malware.
4. Add the printer. On Windows 11: Settings › Bluetooth & devices › Printers & scanners › Add device. On macOS: System Settings › Printers & Scanners › Add Printer.
5. Print a test page and run a scan if this is an all-in-one, so you find any problem now rather than when you are in a hurry.

Ink, toner and supplies

The OKI B721dn uses the following consumables. Match the number exactly when you buy: the same printer family often uses several different cartridge numbers by region.

• OKI B721 black toner (25,000 pages)
• B721 image drum (60,000 pages)
• Fuser unit

High-yield (XL) versions almost always cost less per page if you print regularly. On third-party ink and toner, read our honest assessment first, and note that some manufacturers push firmware that rejects non-original chips.

Full specifications