Why is internet slow on only one device?

If one device is slow and the others in the same room are fast, your internet connection is fine. The problem is that device or its link to the router: usually a weak or crowded Wi-Fi band, a VPN or security app, background downloads, or an old or misbehaving network adapter. A side-by-side speed test tells you which in a few minutes.

Confirm it really is one device

Before changing anything, prove the problem follows the device and not the spot:

1. Put the slow device and a "good" device (a phone works) next to each other.
2. Run the SpeedMetric speed test on both, one after the other, on the same Wi-Fi network.
3. Write down download, upload and ping for each.

If both are slow in that spot, the issue is Wi-Fi coverage, not the device. Our Wi-Fi speed test guide covers that case. If the good device is fast and the slow one is still slow, keep reading.

Then move the slow device to within a couple of meters of the router and test again. A big jump means the device's Wi-Fi radio struggles at range (common with older laptops, TVs and cheap streaming sticks). No change means something on the device itself is holding it back.

Check which Wi-Fi band it joined

This is the most common cause. Many routers broadcast 2.4 GHz and 5 GHz under one network name and let each device pick. A laptop that settles on 2.4 GHz, or stays stuck on it after you walk away and come back, can be several times slower than a phone on 5 GHz in the same chair.

How to check:

• Windows: Settings > Network & internet > Wi-Fi > your network's properties shows "Network band".
• macOS: hold Option and click the Wi-Fi icon. The "Channel" line shows 2.4 GHz or 5 GHz.
• Android: tap the connected network in Wi-Fi settings. Many phones show frequency or Wi-Fi standard.
• TVs and consoles: look in the network status screen. Some only list the channel number. Channels 1 to 14 are 2.4 GHz, and 36 and above are 5 GHz.

If the slow device is on 2.4 GHz, try giving the 5 GHz band its own name in the router settings and joining that directly. Some older devices can't see 5 GHz at all, which settles the question. Our 5 GHz vs 2.4 GHz comparison explains the range-versus-speed trade.

Turn off VPN, proxy and security tools

A VPN sends all traffic through a distant server, so it can cut speed and add ping on that device only. Corporate laptops often run a VPN or security agent you didn't install. Antivirus suites with "web protection" can also inspect every download.

Disconnect the VPN, pause web filtering, and test again. If speed returns, the tool is the bottleneck. You can then choose a closer VPN server, use split tunnelling, or ask IT. Does a VPN slow your internet? covers the details.

Also check for a manually set proxy (Windows: Settings > Network & internet > Proxy; macOS: Wi-Fi details > Proxies) or a custom DNS server you no longer use. A slow DNS server makes pages hesitate before loading even when the speed test looks fine. Our DNS and speed post explains when that matters.

Look for background traffic

One device can be busy without you noticing:

• System updates (Windows Update, macOS updates, console patches)
• Cloud sync such as OneDrive, iCloud Photos, Google Drive or Dropbox
• Game launchers updating in the background
• Browser tabs streaming video or running web apps

On Windows, Task Manager > Performance > Wi-Fi or Ethernet shows live throughput, and Resource Monitor's Network tab lists which apps are using it. On macOS, Activity Monitor's Network tab does the same. If something is moving a lot of data, pause it and retest.

Update or reset the network adapter

If the device is slow even right next to the router with nothing running:

1. Restart it. Not sleep, a full restart. It clears stuck drivers and network state.
2. Update the system and the Wi-Fi driver. On Windows PCs, the laptop maker's support page often has a newer driver than Windows Update.
3. Forget the network and rejoin. This clears a saved profile that may have the wrong security mode or band.
4. Reset network settings. Windows has "Network reset". iPhone and Android have "Reset network settings". You'll need to re-enter Wi-Fi passwords afterward.
5. Check power saving. Some laptops lower Wi-Fi power on battery. Plug in and test again, or set the adapter's power plan to maximum performance.

Test it on Ethernet if you can

A cable removes Wi-Fi from the picture. If the device is fast on Ethernet and slow on Wi-Fi, its wireless adapter or antenna is the weak link. A USB Wi-Fi adapter or a newer device fixes that. If it's still slow on a cable, the cause is software on the device, or a port or cable limit.

Watch the port speed. Some smart TVs, older laptops and USB-to-Ethernet dongles have 100 Mbps ports, which cap any faster plan at a little under 100 Mbps in a test. Check the device's spec sheet or the link speed shown in its network settings.

Check the router's rules for that device

Routers can treat devices differently. Open the router's app or admin page and look for:

• Parental controls or schedules attached to that device
• Bandwidth limits or QoS rules that give it low priority
• Guest network isolation, which some routers also rate-limit
• MAC address filtering or a blocked list that leaves the device half-connected

Remove any rule you didn't mean to set and test again.

Smart TVs and streaming sticks

TVs are a special case. Their Wi-Fi hardware is often modest, they sit behind cabinets or on walls, and their built-in speed tests aren't very precise. If streaming buffers only on the TV:

• Use Ethernet if the router is near, even with a 100 Mbps port. That's plenty for 4K: Netflix recommends 15 Mbps per 4K stream.
• Move a streaming stick away from the TV's back panel with a short HDMI extender cable (many sticks come with one).
• Update the TV's firmware and the streaming app.
• Restart the TV fully. Many TVs only sleep when you press the power button, so unplug them for a minute.

When it's not the device after all

If every check passes and the device still lags only in certain apps, the slowness is probably on the far end: the app's servers, a game server far away, or a site under load. If more devices start slowing down too, switch to our step-by-step debug guide, which starts at the router and works outward.