Size and capacity
Standard table-top dishwashers are slightly larger than a microwave oven, and have a small capacity of between 4 and 6 place settings (meaning they can wash enough cutlery, plates, and other utensils for 4-6 people). Just check the specifications of your replacement options to make sure you get the right size and capacity for your kitchen.
Dry cycle
Some models come with a dry cycle; check your replacement options to see if they include this feature.
Pump and water heater
If the water draining out of the table-top dishwasher needs to go upwards (as it would if it’s placed below the level of the drain), then you’ll need a model with a pump.
Most counter-top dishwashers come with water heaters with varying power. Those dishwashers that have a water heater usually have two or more settings to vary the power of the heater.