The three problems people call "slow Wi-Fi"
When a page takes forever to load, most people blame "the Wi-Fi." But Wi-Fi is only the last few metres of the journey. There are three separate things that can be slow, and they behave differently:
- The line into your home is slow. Your provider is delivering less than you think, or the neighbourhood is congested at 8pm. Wi-Fi is fine; there just isn't much arriving.
- The radio link between router and device is weak. The line is fast, but the signal has to get through two walls and a fridge, so your laptop only sees a fraction of it.
- Something is eating the bandwidth, or one device is broken. Everything is healthy except that a console is downloading a 90 GB update, or one particular laptop has a driver problem.
These get confused constantly. Someone with problem 1 buys a mesh system and is furious when nothing improves. Someone with problem 2 shouts at their provider, who tests the line, finds it perfect, and closes the ticket. Ten minutes of diagnosis prevents both.
The four-minute test
You need a speed test site — Speedtest, Fast.com, or your provider's own tool. Run it three times, in three places, and write down the numbers.
Test 1 — Standing next to the router
Stand within a metre or two of the router, with nothing in between, and run the test on your phone. Close other apps first.
This is the best case your setup can produce. If this number is close to the speed you pay for, your line and your router are both fine — skip ahead to the radio and device sections. If it's far below what you pay for, your problem is the line, and no amount of router fiddling will help.
Test 2 — Where you actually use it
Now go to the sofa, the bedroom, the garden — wherever it feels slow — and run the same test.
Compare it to test 1. A drop of 20–40% at distance is normal and nothing to worry about. A drop of 80% or more means the radio link is your problem. If you get 300 Mbps beside the router and 15 Mbps on the sofa, the sofa is where you need to work, not the provider's helpline.
Test 3 — On a cable, if you can
If you have a laptop with an Ethernet port or an adapter, plug directly into the router and test again. This removes Wi-Fi from the equation entirely.
If the cable is fast and Wi-Fi next to the router is slow, the router's radio is the weak point — often an old router, or one buried in a media cabinet. If the cable is also slow, it is definitively the line, and you have a strong case to take to your provider.
Providers advertise in megabits per second (Mbps); download managers usually show megabytes per second (MB/s). Divide by 8 to convert. A 100 Mbps connection downloading at 12 MB/s is running at full speed, not at a tenth of it. A surprising share of "my internet is slow" complaints are this arithmetic.
Fixing a weak radio link
This is the most common finding, and the good news is that most of the fixes are free.
1. Move the router — properly
The single biggest gain, and the one people skip because the router lives where the cable comes in. Radio waves are absorbed by water, metal, and dense masonry. That means the worst places for a router are: inside a cabinet, on the floor, behind a television, next to a boiler or a fish tank, or in a corner of the house at ground level.
The best place is central, out in the open, and raised — a shelf about chest height, with its antennas visible. If the router has to stay by the front door, that's what a longer Ethernet run or a mesh node is for. Moving a router from a floor-level cupboard to an open shelf routinely doubles the speed two rooms away.
2. Make sure you're on the right band
Modern routers broadcast on 2.4 GHz and 5 GHz, and newer ones add 6 GHz. They behave very differently:
| Band | Speed | Range and walls | Best for |
|---|---|---|---|
| 2.4 GHz | Slowest | Best range, passes through walls well | Far rooms, smart home gadgets, garden |
| 5 GHz | Much faster | Shorter range, weakens through walls | Same room or next room: streaming, calls, gaming |
| 6 GHz (Wi-Fi 6E/7) | Fastest | Shortest range, needs near line-of-sight | A fast device in the same room as the router |
Many routers present all bands under one network name and steer devices automatically. That mostly works, but devices are famously reluctant to move back to 5 GHz once they've latched onto 2.4 GHz — so a laptop that got a weak signal in the garden may still be crawling along on 2.4 GHz hours later, sitting next to the router. Toggling Wi-Fi off and on forces it to re-choose.
If steering keeps making bad choices, split the bands into two named networks in your router settings (for example "Home" and "Home-5G") and connect deliberately. It's slightly less tidy and considerably more predictable.
3. Change the channel — but only on 2.4 GHz
In a block of flats you may have thirty neighbouring networks fighting for the same airspace. On 2.4 GHz there are only three channels that don't overlap: 1, 6, and 11. Any other setting partially overlaps two of them and makes things worse for everyone.
Use a Wi-Fi analyser app to see which of 1, 6, and 11 is least busy near you, then set your router to it manually rather than leaving it on "auto" — auto often picks once at boot and never revisits the decision.
On 5 GHz there are far more channels and congestion is rarely the issue, so leaving it on auto is usually right.
4. Check what your devices actually support
A gigabit line and a Wi-Fi 7 router cannot help a laptop whose card is Wi-Fi 4 from 2013. The link runs at the speed the slower end supports. If one old device is the only slow one on the network, the device is the problem — a USB Wi-Fi adapter costs very little and skips the internal card entirely.
5. Fix interference you can control
Microwave ovens, older cordless phones, some baby monitors, and cheap wireless doorbells all transmit in the 2.4 GHz band. If your Wi-Fi collapses for ninety seconds at a time and someone is reheating soup, that's not a coincidence. Move the router away from the kitchen, or move affected devices to 5 GHz.
6. Add coverage properly, not with a cheap repeater
If a large or awkwardly shaped home genuinely can't be covered from one point, add hardware — but choose carefully:
- Mesh systems are the right answer for most homes. Nodes coordinate with each other and hand devices over as you move.
- A wired access point — a second router or AP connected by Ethernet — is the best possible result if you can run a cable, because the backhaul is not competing for airtime.
- Single-band repeaters, the cheap plug-in "boosters", receive and retransmit on the same radio. That roughly halves throughput for everything connected to them. They extend the area where you have a bar of signal; they do not extend the area where you have usable speed.
Fixing a slow line
If test 3 was slow on a cable, the Wi-Fi is innocent.
7. Confirm what you're actually paying for
Find your current plan on your provider's account page — not the leaflet from when you signed up. Introductory speeds expire, plans get restructured, and "up to" is doing heavy lifting in most advertising. If you're paying for 50 Mbps, 45 Mbps is a healthy result, not a fault.
8. Test at different times of day
Run the same test at 10am and at 9pm. Shared infrastructure — cable and some fixed-wireless networks especially — congests in the evening peak. If you get 200 Mbps in the morning and 30 Mbps at nine at night, the local segment is oversubscribed. That's a provider problem, and it's one worth reporting with your logged numbers.
9. Check the physical link
Look at the modem or ONT. Errors here are unglamorous and common: a coax connector that's finger-tight instead of seated, a phone line with a corroded contact, a fibre patch cable kinked behind a cabinet, or an Ethernet cable damaged where a chair leg lives. Reseat everything. If a cable looks crushed, replace it — Ethernet cables are cheap and failing ones can silently drop a gigabit link to 100 Mbps.
10. Restart the modem, then the router, in that order
Yes, this cliché. Power off the modem and the router, wait thirty seconds, power the modem on first and let it fully sync — usually a solid rather than blinking light — then power on the router. Doing it in that order matters, because the router negotiates its connection when it comes up. Do this only after the tests above, not instead of them.
Fixing a device or a bandwidth hog
11. Find what's downloading
If everything is slow for everyone, something is saturating the connection. Common culprits: a games console applying a patch, a phone backing up photos over Wi-Fi, a computer downloading a major OS update, cloud storage re-syncing a large folder, or someone streaming in 4K on three screens.
Many routers have a "connected devices" or "traffic" page that shows current usage per device. Failing that, pause the obvious suspects one at a time and re-test. Consoles in particular are worth setting to download only overnight.
12. Rule the device out
If only one device is slow while others are fine, stop debugging the network. On that device:
- Turn off any VPN and re-test. A VPN routing you through another continent will cut your speed substantially and add latency; that's expected behaviour, not a fault.
- Update the Wi-Fi driver (on Windows, through the manufacturer's support page rather than Windows Update, which often has an older version).
- Try a different browser, and try the speed test in a private window with extensions disabled — a misbehaving extension can throttle a browser while the rest of the machine is fine.
- Forget the network and reconnect, which clears a stale or badly negotiated connection.
Four things that waste your money
- "Wi-Fi boosters" advertised on social media. The small plug-in devices sold for a few dollars with claims of "up to 10x speed" are typically low-grade single-band repeaters. See the point about halved throughput above.
- Changing DNS to "make the internet faster". A different DNS resolver can shave a few milliseconds off the first lookup for a site and may be worth doing for privacy. It does not change your bandwidth at all. If pages load slowly after they start, DNS is not your issue.
- Upgrading your plan to fix a coverage problem. If you only get 20 Mbps in the bedroom because of two brick walls, paying for a gigabit line changes nothing in the bedroom. Fix the radio link first, then decide whether you need more line speed.
- Expensive antennas on a consumer router. Gains are small and directional. Router placement beats antenna upgrades almost every time, for free.
Slow everywhere, even on a cable → the line, or your plan.
Fast at the router, slow across the house → placement, band, or coverage.
Slow only in the evening → neighbourhood congestion; report it with numbers.
Slow on one device only → that device: VPN, driver, or browser.
Slow for everyone, suddenly → something is downloading.
When to call your provider — and what to say
Call when you have evidence: wired speed tests, well below plan, taken at several times of day, over several days. Write down date, time, download, upload, and latency for each.
Say something close to this: "I'm on the [X] Mbps plan. Connected by Ethernet directly to the modem, I'm getting [Y] Mbps at [times], measured on [dates]. Wireless is not involved. Can you check the line and the local segment?"
That framing skips the first twenty minutes of the script, because you've already ruled out everything they were going to ask you to try. If the line tests clean and the speeds are still low at peak, ask specifically whether your segment is oversubscribed — that's a capacity issue on their side and it needs to be logged as one.
The short version
Test next to the router, test where it's slow, and test on a cable. Those three numbers tell you which of the three problems you have. Then fix that one problem, rather than working through a list of twelve tips that were written for somebody else's house.