Many bedside digital clocks use white LED digit displays and offer adjustable brightness or dimmer settings. Typical controls include multi-step brightness (for example, three levels) or simpler high/medium/low/off options.
Most units are mains-powered and include a battery backup to preserve time and alarm settings. Common backup options cited include 2 AAA alkaline cells or a single CR2032 lithium coin cell; at least one model lists a built-in/non-universal lithium-ion battery.
Many clocks include USB charging ports (some offering 2 AMP rapid charge), and a few models add wireless Qi charging stands in addition to USB ports for charging phones at the nightstand.
Some models project the time onto a wall or ceiling, others use a mirror-style display, and several include color or color-changing nightlights with adjustable brightness and sleep-timer options.
Reviewers commonly praise clear, readable digits and adjustable brightness settings—noting large, easy-to-read displays and multiple dimming steps that improve visibility both at night and during the day.