Ninja FlexFlame Grill Review

Grills can be divisive: Some purists snub anything but lump charcoal, while others love the simplicity and convenience of propane. So, what would the grilldom think about, say, a gas grill that not only promises to char burgers but also to smoke, griddle, and bake? This amalgam does exist: The Ninja FlexFlame.

As a middle-ground kind of griller—I think lump charcoal is great, but there’s no getting around the practicality of propane—I was intrigued by the FlexFlame but also skeptical. Any appliance that promises to do many things often doesn’t do them all very well. To find out if the FlexFlame was the grilling multitasker it claimed to be, I tested it for over a month, searing burgers, grilling sausages, and even baking pizza. 

The Tests

• Setup and Ease-of-Use Tests: I noted how it was to set up the grill and if it was easy to use. I also timed how long it took for the grill to reach 500°F. 
• Grill Test: I used the Ninja to grill a variety of foods, including corn, burgers, and kielbasa. 
• Griddle Test: I used the included griddle to sear smash burgers. 
• Pizza Test: I used the included pizza stone to bake a pepperoni pizza. 
• Smoke Test: I used the grill to cold smoke deviled eggs to see how well the hopper and smoker worked. I tried Ninja’s pellets to evaluate their quality and see if the flavor they imparted was subtle and sweet or acrid and smoky. 

What We Learned

It’s Electric! (And Finicky to Start)

I’m used to simple propane grills: To set up my Weber gas grill, I just attach the propane tank and twist the ignitor dials. But in addition to needing propane, the Ninja, with its multitasking personality, has to be plugged in. Its cord is seven inches long, so you’ll probably need an extension cord. To turn the FlexFlame on, you have to push the dial in, twist it to ignite the burners, then turn it to your desired setting (grill/pizza, two-zone, roast/bake, or low and slow). Each setting corresponds to a different temperature, but these can be adjusted by turning a different dial. 

The power dial is finicky. I had to push it in and turn it back and forth a few times before it ignited the burners. While this isn’t a major flaw, I prefer the simplicity and straightforwardness of a non-electric gas grill. Plus, electronics outside = higher chance of malfunctions. (The electric box also hangs down at an angle from under one of the side tables; I couldn’t screw it in tight enough for it to be parallel to the table.)

I did, however, like the digital screen that shows the temperature. It was clear and bright, and it was easy to adjust the grill temperature; I wasn’t stuck with a preset. 

Thanks to Its Fan, It Heated Up Quickly and Grilled Well 

The Ninja has a built-in fan akin to that of a pellet grill. This creates an even flow of heat when the lid’s closed, and if you’re using the smoker, it draws smoke into the cooking chamber from the hopper. It also helps the grill heat up quickly; it reached 500°F in just over six minutes. 

The downside to this convection system is that it sounds like an airplane taking off. Lifting the lid stops the fan and gives you respite from the noise, but once it’s closed, it’s back to the runway.  Despite that, the FlexFlame did a good job grilling. Hot dogs, sausages, and corn got deep char marks and cooked quickly. If you want a solid propane grill, it’ll do. 

Let’s Talk About the FlexFlame’s Other Features 

The Ninja is a decent grill, but what about its other abilities? It did pretty well in all but one of them. The half-griddle, while cramped, seared lacy, caramelized smash burgers, and the pizza stone ensured a crisp-crusted pizza that baked quickly. The smoker wasn’t as successful: The hopper was small, and the pellets burst into flames during my tests. While smoking does involve burning pellets, it should be a slow burn, not a rip-roaring flame that singes your fingers. The burning pellets emitted an acrid burnt-rubber smell and imparted a smoky taste to the deviled eggs—perhaps a smidge too bitter to be called a total success. 

The Verdict

The Ninja FlexFlame is a good gas grill. It heats up fast thanks to its powerful (and loud) convection fan, and it gets a nice sear on sausages, corn, and burgers without scorching them. The dial to turn on and ignite the grill was finicky, though I did like its bright, clear digital display. Almost all of its additional features performed well, even if they weren’t groundbreaking—anyone can throw a griddle or a pizza stone on a grill. It struggled as a smoker, though, creating a pellet inferno rather than a gently smouldering heap. Overall, it’s a good grill, though I think it’s expensive considering that its additional features weren’t mind-blowingly awesome. If you’re just using the grilling bit, you could save yourself a couple hundred bucks and spring for a Weber instead. 

The Pros

The Ninja FlexFlame is peddled as a multitasker, but at its heart, it’s a grill—and a good one, too. While it’s fiddly to get started, once the flames are cranking, it heats up fast. Foods cook quickly, too, thanks to a powerful (and airplane-engine-loud) fan that distributes the heat: Sausages were burnished and blistered, and burgers were nicely charred but still moist inside. This convection fan helped bake pizza quickly, ensuring puffy edges and a crisp undercarriage. 

While the pellets caught fire when I used the smoker, it did impart a sultry, smoky hickory flavor to cold-smoked deviled eggs. Overall, it excelled as a grill and performed okay in its other duties. 

The Cons 

It took me over an hour to assemble the grill—there were a ton of screws and parts. To start the grill, you have to plug it in, then twist the knob to turn the electric interface on and ignite the flames. Sometimes I had to turn the knob back and forth a few times before it would light and engage. I didn’t love the fact that you need to plug the grill in for it to work; if anything goes wrong with the electronics, you’ve lost much of the grill’s functionality. The cord is also a mere seven inches long, so I needed to use an extension cord. 

While the Ninja FlexFlame got hot fast and grilled well, its other functions weren’t as impressive, particularly the smoker. When I cold-smoked some deviled eggs, the pellets caught on fire, shooting out flames when I opened the hopper. The grill’s fan sounds like a plane taking off. 

Key Specs

• Cooking area: 424 square inches
• Number of burners: 3
• Number of wheels: 2
• Number of side tables: 2
• Warranty: 10 years
• Good to know: Pizza stone and griddle aren’t included in the basic package
• Natural gas available: No
• BTUs: 37,000

Why We’re the Experts

• Grace Kelly is a senior editor at Serious Eats. 
• She’s been testing kitchen equipment for four years. 
• She has two gas grills, two charcoal grills, two pizza ovens, and a smoker—suffice it to say she knows outdoor gear.