Which ink does the HP OfficeJet Pro 8610 use?

The HP OfficeJet Pro 8610 uses HP 950, HP 950XL and HP 951XL.

No. The HP OfficeJet Pro 8610 is an inkjet, so it prints with liquid ink from a cartridge, not toner powder, and no toner cartridge fits it. If you were searching for OfficeJet Pro 8610 toner, the part you want is HP 950, HP 950XL and HP 951XL.

Yes. Besides the standard cartridges it accepts HP 950XL and HP 951XL. A high-yield XL holds more ink and costs less per page, which is worth it if you print often.

HP names the OfficeJet Pro 8610 in the support document listing the inkjets its cartridge blocking firmware reached, so a compatible cartridge can be refused after an update. HP publishes firmware that removes the block on every unit whatever its date of manufacture. The store page for this model carries no notice, so its age is not a safe signal.

Rated yields are the HP 950 at about 1000 pages, the HP 951XL at about 1500 pages and the HP 950XL at about 2300 pages. Real-world yield depends on how much you print and how much ink each page uses.

By list price the lowest cost per page here is the HP 950XL at about 1.8 cents per page. A reliable compatible or remanufactured cartridge can lower that further.