Wireless Keyboards and Mice: 2.4 GHz or Bluetooth

Wireless input devices connect one of two ways, and the choice has more practical consequences than the specification sheets suggest. Neither is better in general; they are better at different things.

2.4 GHz with a receiver

A small USB dongle plugs into the computer and pairs with the device at the factory. Plug it in and it works, with no setup, no pairing and no operating system involvement.

Advantages: it works in the computer’s firmware before the operating system loads, which means it works in a boot menu, in a BIOS screen and during installation. Latency is low and consistent. There is nothing to configure.

Disadvantages: it occupies a USB port, and losing the dongle usually means losing the device — most cannot be re-paired to a replacement receiver. The dongle also protrudes from a laptop and is easy to snap.

Bluetooth

No dongle, no port used, and one keyboard can often be paired with several machines and switched between them.

Advantages: no port, multi-device switching, and works with tablets and phones as well as computers.

Disadvantages: it does not work before the operating system loads, so a Bluetooth keyboard cannot enter a BIOS or select a boot device. Pairing occasionally needs redoing. There is a brief wake delay on some devices, which is enough to lose the first character you type.

Which to choose

• Desktop, plenty of ports, occasional troubleshooting: 2.4 GHz.
• Laptop with two ports and a hub already: Bluetooth.
• Switching between a computer and a tablet: Bluetooth, or a device with both.
• Any machine you might need to boot into a firmware menu: keep a wired or 2.4 GHz keyboard available.

Devices supporting both — a receiver plus Bluetooth, with a switch — are the most flexible and are worth the small premium if you use more than one machine.

Interference

The 2.4 GHz band is shared with Wi-Fi, microwave ovens and a great deal else. Symptoms are stuttering pointer movement or dropped keystrokes, usually worse at a distance.

The fix is nearly always physical: move the receiver closer with a short USB extension, plug it into a front port rather than behind a metal case, and keep it away from a USB 3 port or an external drive, which are notorious sources of interference in this band.

Batteries

Three arrangements. Replaceable AA or AAA cells last months and are trivially replaced anywhere. Rechargeable built-in cells avoid buying batteries and eventually degrade with the device. Rechargeable AA cells sit between the two.

For a mouse, a device that can be used while charging matters — a rechargeable mouse with a port on the front can be used plugged in; one that charges from underneath cannot.

Mouse specifications, briefly

DPI is a sensitivity setting, not a quality measure. An 18,000 DPI mouse is not more accurate than a 1,600 DPI one; it simply moves further per inch, and almost nobody uses the top of the range. Adjustable DPI with a button is genuinely useful; a high headline number on its own is not.

Weight matters more than DPI for comfort. A 60 g mouse and a 110 g mouse feel entirely different over a long session, and preference is personal.

Keyboard layout and size

Full-size includes a number pad. Tenkeyless removes it, which brings the mouse closer to the keyboard and reduces shoulder reach — a real ergonomic benefit for anyone who does not enter numbers all day.

Compact layouts move the arrow and navigation keys onto a function layer, which some people adapt to in a day and others never do. If you use arrow keys constantly, look at where they are before buying.

Compatibility

2.4 GHz receivers present as a standard input device and work with essentially anything with a USB port. Bluetooth support depends on the operating system version, and the modifier key layout differs between systems — a keyboard laid out for one will have the modifier keys in a different order on another, which is remappable but worth knowing.

Connection type, battery arrangement and layout are listed on each product in keyboards and mice.

Storing the receiver

Losing the dongle usually means losing the device, since most cannot be re-paired to a replacement. Many mice have a small magnetic or clip storage slot in the battery compartment — use it whenever the mouse travels.

If yours does not, tape the dongle to the underside of the mouse when packing. It is not elegant and it is considerably better than discovering at a client site that the receiver is at home.

Multi-device switching in practice

Keyboards that pair with two or three devices and switch with a key are genuinely useful for anyone with a laptop and a tablet on the same desk. Switching takes a second or two, which is fine for occasional use and irritating if you switch constantly.

Where switching is constant, a physical KVM or simply two keyboards is less frustrating. It is worth being honest about how often you actually switch before paying for the feature.