Undermount Sinks Versus Drop-In Sinks: Pros and Cons

Undermount sinks are bolted to the bottom of a countertop.
Drop-in sinks are installed directly through the top of the countertop.

Cleaning
Winner: Undermount
Drop-in sinks have a lip framing the sink which, over time, collects dust and residue. This raised lip prevents you from sweeping the countertop debris directly into the sink. Cleaning a countertop with an undermount sink, however, is as easy as wiping kitchen crumbs directly into the sink.

Counter-Space
Winner: Undermount
The undermount sink has no outer lip because it is attached under the countertop. The rim of a drop-in sink is noticeable, meaning there is less counter space in contrast to undermount sinks.

Price
Winner: Drop-In
Generally, drop-in sinks have more inexpensive options in comparison to undermount sinks. The undermount sink is the more expensive alternative and will also cost more install. Undermount sinks are made to different specifications due to the intricacies of their installation requirements, making them a pricier option.

Compatibility
Winner: Drop-In
A downside to undermount sinks is countertop material restrictions. The undermount sinks cannot typically be fitted if you have a laminate countertop. A drop-in sink will work with any countertop, regardless if it is laminate or not.