USB 3 and USB-C devices can cause problems with Wi-Fi and Bluetooth connections, but there's a solution

USB 3 and USB-C devices are everywhere, and they offer a great speed boost for peripherals and storage devices. But there's a possible downside that not many people are aware of -- they can have an adverse effect on Wi-Fi and Bluetooth connections.
Written by Adrian Kingsley-Hughes, Senior Contributing Editor

The other day a question from a reader reminded me that there are possible downsides to using USB 3 and USB-C devices.

Quick question – When I plug my USB 3 hub into my Mac I notice that my Wi-Fi connection slows down and sometimes even drops. Any idea what the problem is? Is it a problem with my USB port?

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The problem here is not with the USB port itself, but actually an issue that relates to some USB 3 and USB-C devices.

Some USB 3 devices generate radio interference in the 2.4GHz frequency, and this can have an adverse effect on both Wi-Fi and Bluetooth as they operate on this frequency.

If you are finding that a device is causing problems, here are some things you can do:

  • Use high-quality cables. Cheap cables may lack the shielding required to prevent radio interference from leaking.
  • Use high-quality USB 3/USB-C devices. Cheaper devices can cause more problems.
  • If you are not using a USB 3 device, unplug it and turn it off.
  • If your device has a long cable, move it further away from your computer.
  • Try connecting the device to a different port (which may be further away from the Wi-Fi/Bluetooth antenna in your computer, and improve the connection).
  • Shift your Wi-Fi installation to the 5GHz frequency instead of 2.4GHz (not all routers and device support this). This has no effect on Bluetooth, which always uses 2.4GHz.
  • Reduce other 2.4GHz interference by moving away from devices such as microwave ovens, cordless phones, and baby monitors.
  • If possible, move your router (or yourself) to a better spot to get a better signal.

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