Is mesh Wi-Fi better than a range extender?

For most homes with coverage problems, yes — and the difference is architectural rather than a matter of power.

How a range extender works. It receives the router's signal and rebroadcasts it. The critical limitation is that it uses the same radio to talk to both the router and your devices, so each packet is transmitted twice on the same channel. That typically halves throughput for anything connected through it.

Extenders also usually create a separate network name, so devices do not move between them automatically — your phone clings to the weak original signal while standing next to the extender, which is the most common complaint and is exactly what the design produces.

How mesh differs. Multiple nodes form a single coordinated network:

One network name, with seamless roaming — nodes hand devices between themselves as you move, using standards designed for it.

Dedicated backhaul on better systems: a separate radio band, or an Ethernet connection, carrying traffic between nodes so it does not compete with client traffic. This is what avoids the halving problem, and it is the main thing distinguishing a good mesh system from a bad one.

Centralised management, with band steering and channel selection handled automatically.

Where an extender is still reasonable: one small dead spot, a tight budget, and undemanding use such as a smart speaker or a doorbell.

What beats both. Wired backhaul — running Ethernet to each access point, or using the mesh system's Ethernet backhaul mode. If you can run a cable, do; it removes the wireless bottleneck entirely. Powerline or MoCA adapters are a middle option where cabling is impractical, with performance depending heavily on the house wiring.

Placement matters more than equipment. Nodes should be roughly halfway between the router and the dead zone, elevated, and away from metal, mirrors and appliances.

More nodes is not better — each hop costs throughput.