PoE, PoE+, PoE++: what the plusses actually mean

Power over Ethernet is the reason a UniFi install looks clean: one cable to each access point or camera carries both data and power. The plusses are just power tiers, and they map to real standards:

Two rules cover almost everything. First: a higher-tier port happily powers a lower-tier device — PoE++ ports run af devices fine; the device takes what it needs. Second: the label on the device is the minimum — feed a PoE+ access point from a plain PoE port and it will either underperform or refuse to boot, usually at the least convenient moment.

The budget, again

Each switch also has a total PoE budget shared across its ports. A switch can have eight PoE+ ports and still not run eight hungry devices at once if the total exceeds the budget — the Lite 8 PoE, for instance, shares 52W across four powered ports. This is the spec people miss, and it's why the PoE budget calculator exists. Size to about 70% and sleep well.

When you don't need a PoE switch at all

One device, one adapter. The single-port injectors cover odd corners of a network without upgrading the whole closet: U-PoE ($9), U-PoE+ ($19), 2.5G PoE+ ($25) for a WiFi 7 AP on a multi-gig run, and U-PoE++ ($35) for the heavy stuff.

The clever trick: PoE in

Some switches accept PoE input — the Switch Ultra ($159) and Ultra 60W ($199) can be powered by the upstream switch and then power devices themselves (output budget depends on how they're fed — check the product page). That's a garage or attic micro-closet with zero outlets used.

Building the whole thing? The kit builder runs these power checks automatically and warns you before checkout, not after install.

Prices current at publication. Browse PoE adapters & accessories and Switches.