Does a wifi booster work, and when will it help?

It can extend usable coverage when it receives a stable signal from the router. Performance depends on placement, obstacles, interference and the backhaul connection.

It may improve speeds in a weak-coverage area, but it does not increase the speed supplied by your internet plan. A wireless hop can also reduce throughput compared with a direct router connection.

Place it between the router and the dead zone, where it can still receive a solid router signal. Avoid hiding it behind furniture or placing it inside the area with no reception.

Mesh is often a better fit for consistent coverage and roaming across several rooms or floors. A single extender can be simpler when only one area needs help.