Answer one question first: is it Wi-Fi, or is it the line?
Most complaints about slow internet are aimed at the wrong target. Before touching any settings, run one test: connect a computer directly to the router with an Ethernet cable and repeat your speed test. If the wired speed matches your plan, the problem is on the Wi-Fi side and the steps below will fix it. If the wired speed is low too, no amount of Wi-Fi tuning will help; the issue is your plan or your line. Ofcom advises the same: use a wired connection to measure your real speed.
A full signal bar does not mean speed
This is the most common confusion. Signal strength tells you how clearly your device hears the router; speed depends on how free the air is at that moment. Four bars with terrible speed is perfectly normal in a block of flats, because dozens of neighbouring networks are talking on the same channel. Signal is about distance; speed is about crowding.
Router placement: the cheapest, most effective change
Ofcom's guidance for home users is refreshingly concrete: the router should sit near the centre of the home and off the floor (on a shelf, for instance), and if it has more than one aerial, the aerials should point in different directions. The materials that block the signal most are water, metal and glass, so next to a fish tank, a radiator or a metal cabinet is a bad spot. Microwave ovens, cordless phones, baby monitors and even some string lights interfere directly on 2.4 GHz. The router living in the corner where the cable arrives isn't a rule, just convenience — and in most homes that's where the biggest loss comes from.
2.4, 5 or 6 GHz?
The three bands do different jobs:
- 2.4 GHz: Passes through walls best and travels furthest. But it's narrow and crowded: with 20 MHz channels only three don't overlap (1, 6 and 11). Ideal for far rooms and smart-home gadgets.
- 5 GHz: Many more channels, far higher speeds. Shorter range — past two thick walls it's effectively done. Devices in the same room or one wall away belong here.
- 6 GHz: Arrived with Wi-Fi 6E and Wi-Fi 7 and is still nearly empty. According to the Wi-Fi Alliance, Wi-Fi 7 can carry twice the throughput of Wi-Fi 6 using 320 MHz channels in this band, and multi-link operation lets a device use more than one band together.
Most routers broadcast all bands under a single name and let the device choose. That sounds convenient, but once a device has latched onto 2.4 GHz it may stay there even after you walk into the room and sit next to the router. Giving the 5 GHz network its own name ends that problem in one move.
Channel congestion: your building's invisible traffic
Wi-Fi is a shared road. Neighbouring networks on the same channel take turns with yours, and the more networks there are, the longer the wait. If your phone lists more than twenty networks, leaving 2.4 GHz on automatic almost always ends badly. Pinning the channel by hand to whichever of 1, 6 or 11 is emptiest is a free speed increase.
How many Mbps do you actually need?
The FCC's household guide sketches a rough frame: a single person doing basic things needs only a few Mbps, while a busy household running more than one demanding task at once — high-definition streaming, video meetings, online gaming — needs its top tier. The real issue is less total speed than simultaneity: 100 Mbps is generous for one home and tight in another where three streams and a cloud backup run at the same time.
Range extender or mesh?
They are not the same thing. A classic range extender receives and sends on the same band, which roughly halves throughput on that leg. In a mesh system the nodes talk to each other over a separate path, so coverage grows without the same drop. Best of all is feeding mesh nodes with Ethernet wherever the cable can reach.
The slowest device on the network holds everyone up
An old phone or a printer from years ago occupies the air for a long time whenever it speaks, delaying newer devices. The most important thing recent Wi-Fi generations brought is less raw speed than a better way of ordering that queue. In a home with many devices, your router's generation can matter more than your broadband plan.
Note: this quiz is designed to estimate the weakest link in your setup; it is not a remote diagnosis of your equipment. If the problem persists after the cable test, asking your provider for a line test is the right next move.