Men installing a generator.

Portable generators and home standby generators—also called stationary generators—perform the same basic tasks, but the two types couldn’t be further apart when it comes to cost and convenience. 

All of the portable generators in our ratings run on gasoline. They burn through 12 to 20 gallons per day, depending on the output of the generator and the load it’s powering.

Manufacturers also make portable generators that can run on liquid propane, natural gas, or diesel fuel, but Consumer Reports does not currently test these models since they represent a small percentage of the market. (It's worth noting that in the aftermath of a storm, it may be more difficult to find portable cylinders of liquid propane, natural gas, or diesel fuel.)  

All portable models tend to be noisier and produce less power than standby models, and they need to be wheeled out of storage, connected to your home’s circuit-breaker panel, and manually fired up in the event of an outage. If you use one during inclement weather, such as a rainstorm—not unlikely during a power outage—you’ll need to protect your generator from the elements with a model-specific cover or a freestanding canopy. 

More on Generators

Home standby generators are permanently installed by a pro and have insulated weatherproof housings that keep them relatively quiet. The big advantages are that they kick on automatically when the lights go out and that they produce more watts, enough to power everything in your home at once. Plus they run on natural gas or propane, which means they can operate for days or weeks on a full whole-house propane tank, or indefinitely in the case of natural-gas versions.

“Home standby generators are expensive, but they’re the gold standard in backup power, and they outperform all other types of generators in our ratings,” says Dave Trezza, who oversees generator testing for Consumer Reports. “If you can afford it, I’d tell you to pick a home standby generator every time.”

Despite all that, far more people choose portable generators for one simple reason: price. Here, we catalog the pros and cons of each type of generator. Our buying guide also offers insights on the merits of each. CR members can read on for ratings and reviews of the top three models in each of the two categories, or for more choices, browse our ratings of 40 models.

Safety first: To run a generator safely, always place it at least 20 feet from the house, with the engine exhaust directed away from windows and doors.
 

Portable Generators

Power output: 3,000 to 8,500 watts
Price range: $400 to $1,500
Fuel needs: 12 to 20 gallons of gasoline per day

Pros: Portable generators are cheaper to buy and install than home standby models. When connected to your home’s circuit-breaker panel with a transfer switch, they can power almost as much as a home standby generator. They have built-in outlets for directly connecting suitable extension cords if you haven’t installed a transfer switch. 

Cons: You’ll need to wheel your generator out of storage, connect it to your transfer switch, and fire it up each time you experience an outage. Portable models also require you to store large quantities of gasoline, mixed with fuel stabilizer, to get through a prolonged outage. They tend to be noisier and have lower output than home standby models. 

Home Standby Generators

Power output: 8,000 to 20,000 watts
Price range: $2,000 to $5,000
Fuel needs: 13 to 48 gallons of liquid propane or natural gas per day

Pros: Home standby generators are largely worry-free. They’re typically sized to power your entire house in the event of an outage, and they come on automatically. They can run for days or weeks without refueling, they tend to be very quiet, and you don’t need to fuss with weather covers. 

Cons: Home standby generators are pricier to buy, and installation costs can range from a few thousand dollars to $10,000 or more. 

3 Top Portable Generators From CR's Tests

Top Picks

1

Power delivery
Power quality
Ease of use

2

Power delivery
Power quality
Ease of use
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3 Top Home Standby Generators From CR's Tests

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Power delivery
Power quality
Ease of use

2

Power delivery
Power quality
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Generator Tips

Damaging storms can happen at any time. On the 'Consumer 101' TV show, host Jack Rico learns from Consumer Reports’ expert, Paul Hope, how to avoid being left in the dark during a power outage.