Both promise to fix wi-fi coverage. They work differently, and the difference determines whether you get more coverage or more coverage at half the speed.

How an extender works

It listens to your router and repeats what it hears.

The limitation is physical. A basic extender has one radio, and a radio can either receive or transmit at a given instant. So every piece of data is handled twice on the same radio, and throughput for anything connected through it is roughly halved.

Better extenders have a second radio dedicated to the link back to the router, which avoids most of the penalty. These cost more and are worth the difference.

The other characteristic is that an extender usually presents itself as a separate network, or as the same name without proper coordination. Your phone connects to one and holds on to it, even when you have walked into the room with the router. That is why people find themselves with three bars of signal and no useful speed.

How mesh works

Two or three units designed together as a single system.

They coordinate: they know about each other, they know which unit each device is connected to, and they actively encourage devices to move to the best one as you walk around. That handover is the main practical difference.

Most mesh systems also dedicate a radio to communication between units, so the traffic between them does not compete with your devices.

Setup is generally simple, managed from a phone app, and the whole house appears as one network name.

Which to buy

An extender if you need coverage in one specific place, that place is not far from good existing signal, and speed there does not much matter. The garage, the shed, a spare room used occasionally.

A mesh system if coverage is poor across a meaningful part of the house, if you move around while on video calls, or if several people are using it at once. This is the answer for most houses.

Wired access points if you can run cable. Better than either, for the reasons in home wi-fi that covers the whole house.

Buy for the house rather than the room. Fixing one dead spot with an extender frequently reveals the next one.

Placement, which matters more than the product

The commonest mistake is placing the unit in the room with no signal. It has nothing to relay, so it produces a strong signal carrying almost no data.

Place it roughly halfway between the router and the problem area, where the existing signal is still good — two or three bars at minimum.

Other rules:

  • Out in the open, not in a cupboard or behind furniture
  • Not on the floor
  • Away from televisions, microwaves and cordless phone bases
  • For multi-storey houses, consider vertical placement — signal travels between floors reasonably well unless there is underfloor heating

Most mesh apps include a placement check that tells you whether a unit is too far from the others. Use it, and move things until it is satisfied.

Connect them with cable where you can

The single biggest improvement available to a mesh system.

A unit connected back to the router by network cable spends no radio time talking to the router. All of its capacity serves your devices, and the whole system performs as though each unit were the main one.

If you have a cable running to another room for a television or a games console, a mesh unit there will be considerably better than one relying on radio. Even one wired unit in a three-unit system helps.

What neither will fix

A slow broadband connection. Mesh distributes what you have; it does not create more. If a device plugged directly into the router is slow, the problem is upstream — see broadband speed troubleshooting.

An old router as the base. Some mesh systems replace the router entirely, which is usually the better arrangement. Adding mesh behind an ageing provider router can leave you with two devices both trying to manage the network, which causes odd behaviour.

One faulty device. If a single laptop is always poor while everything else is fine in the same place, that laptop is the issue.

Practical advice on buying

Two units cover most homes; three suits larger or awkwardly shaped properties. Buying a three-pack and using two is fine; adding a matching unit later is usually possible.

Mixing brands generally does not work — the coordination that makes mesh worthwhile is proprietary.

Check whether the system requires an ongoing subscription for features you expect, and whether it phones home with data you would rather it did not.

Our support team installs and configures home networks across Suffolk and Norfolk, including running the cable that makes it work properly. Get in touch.