Suction power is key: A vacuum is the one purchase that you hope sucks a lot. Suction power is typically measured in Pascals (Pa), with most current vacs ranging between 1,500 Pa and 3,000 Pa. Stronger sucking will be needed to pick up heavier pieces of debris (be sure to set a no-go zone around Legos) and to pull matted-down pet hair from rugs.

Know your floor type: Carpeting and high pile rugs will probably require stronger suction than hard floors, as well as special features like an extra-wide or self-cleaning brush roll to prevent hair from wrapping and clogging. Folks in homes with multiple floor types might consider a bigger, sturdier robot vacuum that can hurl itself and its wheels over mats, rugs, and transitions from carpet to hard floors.

Consider automatic emptying: Because robot vacuums are typically under four inches tall, their onboard dust bins are also small — which means they frequently require emptying. (Dustbins fill up particularly quickly in homes with pets.) A self-emptying vacuum takes that job out of your hands, emptying itself into a larger dustbin in its charging dock. These larger bins can typically hold weeks of dirt without needing to be cleaned or dumped out.

Think about your home’s layout: Every robot vacuum is equipped with sensors and drop detection. But if your home has lots of rooms, lots of turns, or lots of close-together furniture, you’ll have fewer navigation issues with an advanced model that uses intelligent mapping to remember exactly how your home is laid out, including labeling of specific rooms, mental notes of staircases, and ability to deploy zone cleaning.

Pay attention to low-profile furniture: No one should have to be scared about what’s accumulated under their couch over the past year. A robot vacuum measuring three inches or less in height should be able to scoot under most low-hanging couches and beds.

Assess battery life and square footage: One of the main complaints people have about their robot vacuum is that it craps out in the middle of the floor. Larger spaces require more time to clean, and it all depends on how annoyed you’ll be if it only finishes a few rooms at a time. Average run times for the list below range between 90 and 200 minutes, which translates to about 500 and 2,800 square feet covered on one charge.

Look for app control: WiFi-enabled robot vacuums can be synced with a smartphone app to control scheduling, manual start, and cleaning settings, as well as telling your vac to make its rounds when you’re not home. Low-end models that don’t connect to WiFi will usually come with a separate remote. If you’re used to asking Alexa or Google to turn off the lights or tell you the weather, a model with voice integration will blend in nicely.