A dishwasher with a dishwasher filter.

What do you think happens to all those soggy bits of food as water and dishwasher detergent circulate through a dishwasher?

They end up in a filter, beneath the bottom rack. 


"The filter prevents food from redepositing debris on clean dishes and clogging the drain," says Larry Ciufo, the engineer who oversees Consumer Reports' dishwasher tests.

Dishwasher filters come in two flavors: self-cleaning or manual. Both are effective, but they work differently. The biggest difference is that you need to clean a manual filter regularly.

Below, we break down more differences in detail.

Check the Features & Specs tab in our dishwasher ratings to see which kind of filter each model has. Also, if you're in the market for a new machine, see our dishwasher buying guide.

Self-Cleaning Filters

Self-cleaning dishwasher filter.
A self-cleaning dishwasher filter.

Self-cleaning filters rarely need your attention. To determine whether this is the type you have, look inside the dishwasher for a plastic grid or series of holes at the base of the machine that cover the filter, as in the photo above.

Self-cleaning filters used to have a grinder that pulverized food so that it easily went down the drain, but they tended to be noisy.

To address the noise issue, many self-cleaning filters now have an ultrafine mesh. The rush of water forces food through the filter, breaking it into tiny particles that wash away.

This type of self-cleaning filter is quieter than one with a grinder and is found on some of the more expensive dishwashers, including some Kenmore and KitchenAid models. You'll see filter types called out in the features & specs page in our ratings and on each model's summary page. 

Good insulation can also dampen the noise a dishwasher makes. That's why some dishwashers with a standard self-cleaning filter still earn decent scores in our noise tests.

Manual Filters

Manual dishwasher filter.
A manual dishwasher filter.

Manual filters tend to be quieter, but they require occasional maintenance. Skip the step of cleaning your manual filter and the food it collects can cause odors and reduce water flow, preventing dishes from getting their cleanest.

To find out whether you have this type, look under the plastic spray arms at the bottom of the tub and you'll see a round plastic part like the one shown above. (It resembles the filter on some carafe water filters.) Arrows on top might indicate which direction to turn the filter for unlocking and locking it.

To clean a manual filter, turn and remove it, then rinse it under running water (see the photo below) until all the debris is gone. Wipe away any gunk that’s stuck to the plastic component. 

Check the owner's manual or manufacturer’s website to find out how frequently you need to clean the filter. But a sure sign it's time is when you start to notice bits of food stuck to dishware after the wash cycle.

Manual dishwasher filter.

Choosing a Dishwasher Just Got Easier

You'll find more than one hundred models from a wide range of brands in our dishwasher ratings. And as important as performance is, brand reliability matters, too.

Our predicted reliability rating estimates the likelihood that newly purchased models from a given brand will break within the first five years. Our owner-satisfaction rating reflects the proportion of CR members who are extremely likely to recommend the dishwasher they bought.

The data come from our survey of CR members' experiences with 74,880 dishwashers purchased between 2007 and 2017 and not covered by a service contract.

To make it easier for you to find the best dishwasher for your budget, we now combine lab test results, predicted reliability, and owner satisfaction into a single Overall Score, which you'll see in our dishwasher ratings.  

Get the Most From Your Dishwasher