As of 2015, some good coffee mug warmers include Mr. Coffee MWBLK Mug Warmer and Deluxe Cozy Cup Warmers, according to Coffee Mug Warmer. Coffee mug warmers come in different shapes and sizes to accommodate all types of coffee mugs.
The Mr. Coffee MWBLK Mug Warmer is activated by a mug, but it also has an on-and-off switch. The warmer works well with mugs that have a flat base to ensure the contents warm up efficiently. The Deluxe Cozy Cup Warmer is UL approved with a 24-watt heating element. The element has a non-stick surface, making it easier to clean after use.