My kitchen counter has always been a battleground between my love for crispy air-fried snacks and my absolute refusal to clutter my workspace. This tension is exactly what led me to the Ninja Foodi Flip series. These ovens are famous for their “origami” trick – flipping up against the backsplash when they aren’t in use – but choosing between the Ninja SP351 (Foodi Smart Dual Heat Air Fry Oven) and the Ninja SP151 (Foodi Digital Air Fry Oven) is a much more nuanced decision than just picking a color.
I’ve spent months rotating these two units through my daily meal prep, using them for everything from 7:00 AM bagels to 9:00 PM late-night pizza sessions. While they look remarkably similar when tucked away, the experience of actually cooking with them is night and day. One is a straightforward, efficient multi-tool that handles the basics with precision, while the other is a high-performance culinary station that aims to replace your cast-iron skillet and your meat thermometer in one fell swoop. If you’re trying to decide if the “Dual Heat” upgrade is worth the extra investment, here is exactly what I discovered during my time with both.
The Key Difference: Ninja SP351 vs. SP151 Air Fryer Oven
The fundamental gap between the SP351 and the SP151 comes down to how they apply heat and how they monitor your food.
- The Ninja SP351 introduces Dual Heat Technology. It uses a specialized SearPlate that heats up to 500F to mimic a stovetop sear, combined with rapid cyclonic air. It also includes an integrated Foodi Smart Thermometer, which allows the oven to shut off automatically when your protein reaches the perfect internal temperature. It offers 13 functions in total.
- The Ninja SP151 is the classic 8-in-1 model. It uses OvenCrisp Technology, utilizing infrared heating elements and rapid air circulation. It is a fantastic all-rounder for air frying and baking, but it lacks the direct-contact searing plate and the internal thermometer system. It is slightly more compact but offers fewer specialized cooking programs.
Comparison Table: Ninja SP351 vs. Ninja SP151 Air Fryer Oven
| Feature | Ninja SP351 (Dual Heat) | Ninja SP151 (8-in-1) |
| Heating Tech | Dual Heat (SearPlate + Air) | OvenCrisp (Infrared + Air) |
| Max Temperature | 500F | 450F |
| Functions | 13-in-1 (Sear Crisp, Griddle, etc.) | 8-in-1 (Air Fry, Roast, etc.) |
| Smart Monitoring | Integrated Smart Thermometer | None (Manual checking) |
| Storage | Flip Up & Away | Flip Up & Away |
| Internal Height | Increased (Fits 2-lb Roast) | Standard (Standard Sheet Pan) |
| Cooking Speed | Up to 65% faster than full oven | Up to 50% faster than full oven |
| Power | 1800 Watts | 1800 Watts |
| Accessories | SearPlate, Basket, Rack, Probe | Sheet Pan, Basket, Rack |
| External Depth | 20.21″ (Deep Profile) | 17.01″ (Shallow Profile) |
| Check Latest Deals on Amazon | Buy on Amazon | Buy on Amazon |
My Take: A Detailed Comparative Review
Design: The Evolution of the Flip
When both ovens are flipped up against my backsplash, they look like professional-grade equipment. The Ninja SP151 has a slightly shallower profile (about 17 inches deep), which I found worked better on my narrower side-counters. It’s a clean, stainless steel box that feels incredibly sturdy. The interface is a digital display with a simple dial – no steep learning curve here.
- DUAL HEAT TECHNOLOGY: The up to 500°F directly heated SearPlate and up to 500°F rapid cyclonic air work together to allow you to sear...
- MAXIMUM VERSATILITY: 13 Functions include Air Fry, Sear Crisp, Rapid Bake, Frozen Pizza, Fresh Pizza, Griddle, Air Roast, Bake, Broil,...
- RECLAIM YOUR COUNTER SPACE: Takes up 50% less space when you flip it up and away to store against your backsplash.
- 8-IN-1 FUNCTIONALITY: Air fry, Roast, Broil, Bake, Pizza, Toast, Bagel, Dehydrate.
The Ninja SP351 is noticeably “beefier.” It’s deeper (over 20 inches), which means it takes up more horizontal space when it’s folded down for cooking. However, Ninja used that extra depth to give the interior more height. One of my biggest gripes with the original SP151 was that I couldn’t fit a thick chicken breast or a small roast without it nearly touching the top heating elements. The SP351 solves this; it feels like a “real” oven inside. The addition of the thermometer port on the side of the SP351 also gives it a more high-tech, “Smart” aesthetic that I really appreciated.
Ease of Use: Manual Intuition vs. Automated Precision
Using the Ninja SP151 is like using a very fast, very efficient toaster oven. I love the 60-second preheat time. In the time it takes me to grab a bag of frozen fries from the freezer, the oven is already at $400^{\circ}\text{F}$. It’s incredibly intuitive – you pick a function, set the time, and go. However, I found myself constantly hovering near it with a handheld meat thermometer when I was roasting salmon or chicken, worried about overcooking.
The Ninja SP351 changed my workflow entirely. The Foodi Smart Thermometer is a game-changer. I plugged the probe into a thick New York Strip steak, set the oven to “Medium-Rare,” and walked away to make a salad. The oven stopped exactly when the steak hit its target temperature. No guesswork, no cutting into the meat to check the color. If you are someone who multi-tasks in the kitchen, the SP351 is significantly easier to use because it “watches” the food for you.
Functions: Searing vs. Roasting
The SP151 is a master of the “Air Fry.” It makes wings and fries that are indistinguishable from deep-fried versions. Its 8 functions cover 90% of what most people need. I found the “Toast” function to be exceptionally even – better than many dedicated high-end toasters.
However, the SP351 introduces functions like “Sear Crisp” and “Griddle.” This is where the SearPlate comes into play. It’s a heavy-duty, non-stick pan that gets incredibly hot. When I made smash burgers in the SP351, I actually got a crust on the meat – something that usually only happens in a cast-iron skillet. The “Fresh Pizza” setting on the SP351 also outperformed the SP151; the direct heat from the SearPlate gave the bottom of the crust that “brick oven” crunch that the SP151’s standard wire rack just couldn’t match.
Maintenance: The Battle Against Grease
Let’s be honest: air fryers get greasy. Both units have a removable crumb tray, which is essential. Because they flip up, you can actually access the bottom of the oven much more easily than a standard toaster oven to wipe away drippings.
The SP351’s SearPlate is dishwasher safe and has a very high-quality non-stick coating. I found it much easier to clean than the standard sheet pan provided with the SP151, which tended to develop “baked-on” stains over time if I didn’t scrub it immediately. However, the SP351 has more internal surface area and more complex heating elements, so a deep clean takes a few extra minutes compared to the simpler interior of the SP151.
Ninja SP351 Dual Heat Smart Oven
- DUAL HEAT TECHNOLOGY: The up to 500°F directly heated SearPlate and up to 500°F rapid cyclonic air work together to allow you to sear...
- MAXIMUM VERSATILITY: 13 Functions include Air Fry, Sear Crisp, Rapid Bake, Frozen Pizza, Fresh Pizza, Griddle, Air Roast, Bake, Broil,...
Pros:
- Dual Heat Technology: Real searing capability that replaces stovetop pans.
- Integrated Thermometer: Perfect results every time without manual checking.
- Increased Height: Fits larger proteins and roasts that would burn in smaller models.
- 13 Functions: Incredible versatility, including specialized pizza and griddle modes.
Cons:
- Larger Footprint: Requires more counter depth when in the cooking position.
- Higher Price: A significant jump in cost for the added tech.
Ninja SP151 Digital Air Fry Oven
- RECLAIM YOUR COUNTER SPACE: Takes up 50% less space when you flip it up and away to store against your backsplash.
- 8-IN-1 FUNCTIONALITY: Air fry, Roast, Broil, Bake, Pizza, Toast, Bagel, Dehydrate.
Pros:
- Value for Money: Frequently available at a great price point for the performance.
- Compact Depth: Fits better on standard or narrow kitchen counters.
- Fast & Efficient: 60-second preheat and 50% faster cooking than traditional ovens.
- Simple Interface: Perfect for those who want a “no-fuss” appliance.
Cons:
- Low Clearance: Limited to flatter foods; you can’t roast a whole chicken or tall breads.
- No Precision Probe: You’ll need a separate thermometer for proteins.
Conclusion and Recommendation
Both of these ovens are spectacular at reclaiming counter space, but they cater to different types of home cooks.
I recommend the Ninja SP151 if:
You are primarily looking for an elite air fryer and toaster. If your diet consists of frozen snacks, toast, bagels, and flat sheet-pan dinners for two, the SP151 is all the oven you need. It’s fast, reliable, and takes up the least amount of space possible. It’s the perfect “upgrade” for someone moving away from a standard toaster.
I recommend the Ninja SP351 if:
You want a legitimate replacement for your full-sized oven and your stovetop. If you cook raw proteins (steaks, chicken breasts, salmon) regularly, the combination of the SearPlate and the Smart Thermometer is worth every penny. The extra internal height makes it a much more “capable” oven for family meals.
My Personal Choice: After using both, I can’t go back from the Ninja SP351. The ability to sear a steak and have the oven tell me exactly when it’s done – all while maintaining that “flip-away” storage – makes it one of the most functional appliances I’ve ever owned.
Frequently Asked Questions
Can I fit a whole chicken in these ovens?
Neither of these models is designed for a whole “rotisserie-style” chicken because of the flip-away design (which keeps the ovens relatively flat). However, you can fit a spatchcocked (butterfiled) chicken in the SP351 quite easily due to its increased internal height.
Is the SearPlate in the SP351 really different from a regular pan?
Yes. It is designed to absorb and hold infrared heat much more efficiently than a standard sheet pan. It mimics the thermal mass of a griddle, which is why it can sear meat while the air fryer circulates heat around it.
Do these ovens get hot on the outside?
Yes, the stainless steel housing does get hot during long cooking cycles. I always make sure there is nothing flammable touching the sides during use, and I wait about 10 minutes after cooking before flipping the unit up to store it.
How does the “Flip” mechanism hold up over time?
In my experience, the hinge is incredibly robust. It’s a heavy-duty spring-loaded system. As long as you aren’t slamming it up or down, it feels like it’s built to last for years of daily use.
Can I use parchment paper in these?
You can, but you have to be very careful. Because the heating elements are so close to the food, parchment paper can easily fly up into the elements and catch fire. I recommend only using it if it is weighted down heavily by food, or sticking to the non-stick SearPlate in the SP351.
