Ok I screwed up.

Ok I screwed up. I’ve been using ws2812 strips for so long and never getting the wrong ones. But today I received. Two rolls marked 12v

Is that even possible?

How to drive them with arduino?

The 12 is only about power - the data signals are still 5v - so you connect data to arduino as normal, you connect + to a 12v power supply positive and (this is important) you connect ground to both ground on the arduino and ground on the power supply.

These Strips are WS2811 not WS2812, its like Daniel said, it works with an Arduino and a 12V power supply.

And I assume if I should have longer runs, 12v could afford smaller gage wire?

Do you want more 2812 IC Strips? Mericana sales9@uniqueentech.com

@Roger_Kolasinski ​ you will find that the 12v strips will give you a longer run before you have to inject power. With 5v strips i inject every 100 leds. With 12v ive gone 500.

The thinner the guage of wire, the more resistance you will present as load. Any decent cable manufacturer has data for volt drop per given length. Else you can find tables online that will give you a good guesstimate, based on material, diameter and length.