Why Your Internet Is Slower Than What You Pay For

Almost always, the line is delivering what you pay for and something between the wall and your device is spending it. The fastest way to know is one wired test: run the speed test on a machine plugged directly into the router.

• Wired result matches the plan, Wi-Fi result does not. The problem is your Wi-Fi. This is the most common case by a wide margin.
• Wired result is also well below the plan. The line, the router, or the provider's network is the problem — and you now have the number to make the call with.
• Both match the plan, but pages still feel slow. The connection is fine; latency or DNS is the issue.

Cause 1 — Wi-Fi (most common)

Wi-Fi is a shared, interference-prone medium, not a cable. Expect a well-set-up network to deliver 50–70% of the line at close range, and much less through walls.

| Situation | What you typically see | | --- | --- | | 2.4 GHz only, older router | 20–60 Mbps, regardless of plan | | 5 GHz, close to the router | 50–70% of the plan | | 5 GHz, two walls away | Half of that again | | Wi-Fi 6, recent devices, close | Close to the line speed | | Mesh satellite on a wireless backhaul | Up to half the plan at each satellite |

Fix the wireless side before anything else: the Wi-Fi audit walks through placement, channel, band and backhaul in about twenty minutes. A cable run to the machine that matters most is still the cheapest upgrade in networking.

Cause 2 — A device that cannot go faster

A laptop with an older wireless card tops out around 100–300 Mbps no matter what the plan says. A phone on 2.4 GHz is capped near 60 Mbps in practice. A USB 2.0 Ethernet adapter tops out around 300 Mbps. Older smart TVs often negotiate 100 Mbps on their wired port and no more.

Check what the device reports: in Windows, Task Manager → Performance → Wi-Fi or Ethernet shows the current link speed. If that number is below your plan, the device is the ceiling.

Cause 3 — Peak-hour congestion

If the connection is fast at 7 a.m. and slow at 8 p.m., that is a shared network doing shared-network things. Cable connections in particular share capacity with the neighbourhood. It is not "throttling" in the conspiracy sense; it is the bus being full.

What to do: run the test at three different times of day and keep the results. A consistent evening drop of more than about 30% is worth reporting to the provider with those numbers attached.

Cause 4 — The plan's own wording

Provider figures are "up to" numbers measured on a wired connection with nothing else running. A few things follow from that:

• Provisioning overhead means 100 Mbps measures about 90–95, and a gigabit measures about 900–950.
• Upload is asymmetric by design on most home connections. A 300/20 plan means a 20 Mbps ceiling on upload, which is the number that ruins video calls and cloud backups.
• "Speed" sometimes means a burst. Some plans advertise a short-term peak the line cannot hold for a whole test.

Read the upload figure on your plan before blaming the download.

The other usual suspects

• A VPN. Encryption and a distant exit server commonly cost 10–40% of throughput, and add latency. Test with it off.
• A saturated upload. One cloud backup or a photo sync running in the background will make everything else feel slow, because upload is the narrow side of the pipe.
• An old router given by the provider years ago. If it is more than five or six years old, it is probably the limit on any plan above 100 Mbps.
• Malware or a "booster" app on the device, eating capacity in the background.
• DNS. Slow lookups make pages feel sluggish while every speed test looks perfect. Changing to a faster resolver is a two-minute test.

A twenty-minute diagnosis, in order

1. Test by cable at the router. Note download, upload, latency.
2. Test on Wi-Fi where you actually sit. Note the same three.
3. Compare both against the plan's download and upload figures.
4. If wired ≈ plan and Wi-Fi is much lower: fix Wi-Fi, not the plan.
5. If wired is much lower: restart the router and modem, test again, then call the provider with the number.
6. If both are fine but the web feels slow: test latency, try a different DNS resolver, and check for background uploads.

Keep a note of each result. Providers respond to a written sequence far better than to "it feels slow", and the arithmetic points to the culprit in almost every case.