What Ink Does the HP OfficeJet Pro 6978 Use?

Quick answer: The HP OfficeJet Pro 6978 uses four individual HP 902 ink cartridges — black, cyan, magenta and yellow. The HP 902XL high-yield versions are rated ~750 pages each against ~300 for standard black, and they are where the cost-per-page saving lives on this machine.

HP OfficeJet Pro 6978 Ink Cartridges at a Glance

The HP OfficeJet Pro 6978 takes four individual cartridges. The same HP 902 / 902XL cartridges also fit the HP OfficeJet 6968 and OfficeJet 6958, and the rest of the OfficeJet Pro 6970 series.

This printer is not an HP+ model — HP+ applies only to printers with a trailing "e" in the name, such as the OfficeJet Pro 8000e and 9000e series. That means the 6978 is not locked to Original HP ink by an HP+ enrolment, which is good news if you want to use compatible cartridges.

Save on HP 902 / 902XL

Castle Ink's compatible and remanufactured HP 902 cartridges can save you 50–70% against genuine cartridges without giving up print quality. Every cartridge is tested, carries a 1-year warranty, and ships free on orders over $50. Shop HP 902XL BCMY 4-Pack and HP 902XL Black, OEM chip for the HP OfficeJet Pro 6978.

How to Replace Ink in the HP OfficeJet Pro 6978

1. Power the printer on and open the ink cartridge access door — the carriage will slide to the center. Wait for it to stop moving before reaching in.
2. Press down on the old cartridge to release it, then pull it forward and out of its slot.
3. Unwrap the new cartridge and pull the orange tab to remove the protective plastic. Do not touch the gold contacts or the copper-colored nozzles.
4. Slide the new cartridge into its slot at a slight upward angle and push up until you hear it click into place.
5. Close the access door. The printer will print an alignment page automatically — keep it long enough to confirm the print is sharp and the colors are right.

Troubleshooting Tips

"Cartridge missing or damaged": Power-cycle the printer with the cartridges installed. If it persists, remove the cartridge, wipe the gold contacts with a lint-free cloth dampened with distilled water, dry thoroughly, and reinsert at the upward angle until it clicks.

Streaky or faded prints: Open HP Smart and run Printer Settings > Tools > Clean Ink Cartridges. Two cleaning cycles clear most nozzle blockages; more than that mostly wastes ink.

Firmware updates rejecting compatible ink: Some HP firmware revisions tighten cartridge authentication. If you intend to use compatible cartridges, turn off automatic firmware updates in HP Smart > Printer Settings > Advanced Settings before you install them.

Alignment page prints blank or skewed: Confirm you removed the orange protective tab from each new cartridge and that both are seated with a firm click, then run alignment again from HP Smart.

Official HP OfficeJet Pro 6978 Resources

• HP customer support — printers
• HP cartridge and supplies finder

Bottom Line

The HP OfficeJet Pro 6978 is well served by the HP 902 family, and the high-yield tier is where the cost per page actually falls. Buy the largest tier your printer supports, keep the model number written down somewhere you can find it, and ink stops being something you think about.

Written and reviewed by William Elward — Founder of Castle Ink, 20+ years in the printer & imaging supplies industry.

Frequently Asked Questions

Does using compatible HP 902 cartridges void my HP OfficeJet Pro 6978 warranty?
No. Under the U.S. Magnuson-Moss Warranty Act, a manufacturer cannot void your printer warranty solely because you use compatible or remanufactured cartridges. If a specific cartridge causes damage, that damage is not covered — but the rest of the warranty stands.

How are these page yields measured?
To the ISO/IEC standard for the cartridge type, at 5% page coverage on plain paper. That is a deliberately modest amount of coverage, so heavy graphics, photos or dense tables will always yield fewer pages than the rating. The numbers are useful for comparing cartridges against each other, not for predicting your exact month.

Is it the OfficeJet 6978 or the OfficeJet Pro 6978?
HP's own product name is OfficeJet Pro 6978. Both spellings are in wide use and both refer to the same printer, which takes HP 902 / 902XL either way.

Can HP firmware stop my compatible cartridges working?
HP does operate a system it calls Dynamic Security that authenticates Original HP cartridges on some product lines, and firmware updates have historically changed that behavior mid-life. HP does not publish a definitive model list, so the safe play on any OfficeJet is to turn off automatic firmware updates before you switch to compatible ink.

Shop Compatible Ink at Castle Ink

Find the right cartridge for the HP OfficeJet Pro 6978 and every other printer we cover on the Find Ink by Printer page, or work through a fault at our printer troubleshooting center.

Buy the HP OfficeJet Pro 6978 on Amazon: HP OfficeJet Pro 6978 on Amazon — as an Amazon Associate we earn from qualifying purchases.

See also: printer says ink cartridge not recognized | faded or streaky prints | printer printing the wrong colors