~ read.

Cafe with working WIFI in Manhattan

This is just a short list of cafes that has wifi fast enough to work. Yelp's list didn't really help because there was a lot of false information.
Starbucks generally works, though if you actually want decent coffee that's not over roasted and blend, you should check out these alternatives.
Special mention to Cafe Frederick Harlem Parlor, quiet setting, plenty of power outlets, and great wifi speed.
Green label means no or none-usable wifi.
Red means good wifi.