Customer Reviews for Ninja DoubleStack XL Smart Air Fryer (SL451)
Item # : 24637555
Model # : SL451
Cook More, Save Space with the Ninja DoubleStack XL Smart 2-Basket Air Fryer: 10-QT Capacity, Smart Cook System, and the Power to Cook 4 Foods at Once!
- SPACE SAVING DESIGN: Ninja's stacked design lets you cook double the food in nearly half the space and still fits under standard cabinets. Plus, it's 40% slimmer than your traditional 2-basket air fryers
- SMART COOK SYSTEM: Achieve the perfect doneness, from rare to well-done, at the touch of a button with the integrated Foodi Smart Thermometer—no guesswork required.
Price is $229.99, Regular price was $269.99, You save 14%
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126 reviews
Most helpful positive review
Posted Apr 22, 2026
Love the Ninja
We bought this for our new apartment and love it. It’s perfect and great to look at as well. Deff recommend
VS
Most helpful critical review
Posted Nov 17, 2025
Beyond disappointed
I bought this to replace my single drawer Ninja air fryer so that I could have two drawers that cook independently but boy do regret that! This does not work very well at all. We tried to cook premade hashbrowns but they took a very long time to crisp up. Same thing with tater tots and everything else we have cooked. I am beyond disappointed and can't return it because...
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BM2026
Reviewed at:
sharkninja.com
Posted Apr 22, 2026
Love the Ninja
We bought this for our new apartment and love it. It’s perfect and great to look at as well. Deff recommend
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Km4k
Reviewed at:
sharkninja.com
Posted Apr 21, 2026
Disappointing
I usually love ninja products but this one has been disappointing. It doesn’t cook the food as well as my old air fryer, seems like the cooking time is much slower. And even though I haven’t had it very long one of the double ovens seems to not been cooking much at all.
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Response from Staples :
Hi there,
Thanks so much for sharing this with us. We’re really sorry to hear that the DoubleStack air fryer hasn’t lived up to your expectations. We know how disappointing it can be when cooking takes longer than expected or when one oven doesn’t seem to be doing its job, especially when you’ve only had the unit for a short time.
This definitely isn’t the experience we want for you, and we’d love the chance to take a closer look and help. Our Support team can walk through your setup and settings with you and review your unit to see what’s going on. You can reach them here whenever you’re ready:
https://support.sharkninja.com/contact-us
We really appreciate your feedback and loyalty, and we hope we can help get things back on track for you.
Sincerely,
Ninja Kitchen
April 21, 2026
Joe Langlois
Verified Buyer
Reviewed at:
Shark Ninja
Posted Apr 15, 2026
awesome
Smaller and more convenient, very practical and much more suitable for my needs
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Nelson
Reviewed at:
Shark Ninja ANZ
Posted Apr 10, 2026
Perfect
Best thing we have ever bought as far as a kitchen appliance is concerned. Very easy to operate and the settings are very accurate. Cooks the food perfectly. Highly recommended
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MNBrrrrrrs
Reviewed at:
sharkninja.com
Posted Apr 10, 2026
Took too long
Need to shake often due to heat coming from back. Cook time when using both baskets was over double what we used to have with previous fryer. Returning.
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Response from Staples :
Hi there,
Thank you for taking the time to share this feedback with us. We understand how disappointing it is when the Ninja DoubleStack doesn’t perform the way you expected, especially with longer cook times when using both baskets.
We appreciate you letting us know about your experience, and we’ll be sure to share this feedback with our team. If you haven’t already returned the unit and would like us to look into this further, please feel free to reach out to us through the link below.
https://support.sharkninja.com/contact-us
Kind regards,
Ninja Kitchen
April 11, 2026
Upbeatmomma
Reviewed at:
sharkninja.com
Posted Apr 5, 2026
Lots of space
I’ve had this for 3 weeks and I love it. It’s so nice to be able to cook 2 food items at the same time. I previously had the Ninja Air Fry Pro Countertop Oven and this one is easier to clean and I can make more food at the same time.
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D&026
Reviewed at:
sharkninja.com
Posted Feb 17, 2026
Easy to use
This is my 1st air fryer. I love it! I have zero complaints. Buy it. You won't be sorry.
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Jenny8675309
Reviewed at:
sharkninja.com
Posted Nov 17, 2025
Beyond disappointed
I bought this to replace my single drawer Ninja air fryer so that I could have two drawers that cook independently but boy do regret that! This does not work very well at all. We tried to cook premade hashbrowns but they took a very long time to crisp up. Same thing with tater tots and everything else we have cooked. I am beyond disappointed and can't return it because...
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Response from Staples :
Hello,
Thank you for taking the time to provide your feedback.
We understand this has caused a lot of frustration, and we're here to help. Something doesn’t seem quite right about how your product is performing; we’d like to make sure it’s working as it should. Please give our team a call at 1-800-365-0135 so we can help with this.
Our team is available:
📞 Monday–Friday: 9 a.m. – 9 p.m. ET
📞 Saturday: 9 a.m. – 6 p.m. ET
Kind regards,
Ninja Kitchen
November 17, 2025
RiaJ
Reviewed at:
Shark Ninja ANZ
Posted Oct 30, 2025
Awesome. Go ninja
First air fryer. Very happy with it. Love the space saving.
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PatsyCur
Reviewed at:
sharkninja.com
Posted Oct 24, 2025
Super
I am veryyy happy with my purchase! Loving this in my new kitchen...
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Anonymously
Verified Buyer
Reviewed at:
Shark Ninja
Posted Oct 17, 2025
Design flaw
The insert for double cooking doesn’t sit properly and if any food is placed on it it falls on top of whatever is cooking underneath and almost impossible to remove once it drops as it is hot..
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Ninja Girl
Reviewed at:
sharkninja.com
Posted Jul 24, 2025
The Best Air Fryer!!!!
Great for small kitchens with limited counter space. It has lots of valuable features and meets my expectations. I have never regretted any of the Ninja products I have purchased.
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Berny
Reviewed at:
sharkninja.com
Posted Jul 4, 2025
Nice but…
Although I love all my Ninja products I unfortunately had to send this back. Yes it has dual baskets but I find them to be too small for my needs.
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Response from Staples :
Hello Berny,
Thank you for taking the time to leave a review.
We're so sorry to hear that the Ninja DoubleStack wasn’t the right fit for you. We will absolutely share the feedback you’ve provided with the relevant teams for
consideration on future products. We hope you’ll give our products another try in the future.
Kind regards,
Ninja Kitchen
July 7, 2025
Des 123456
This reviewer received a free product or coupon in exchange for an unbiased review of the product
Reviewed at:
Shark Ninja ANZ
Posted May 31, 2025
Looking forward to cooking some yummy food in my n
Yes I bought this beautiful airfryer xxxL about one week ago now,So looking forward to seeing how it goes.
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Le_ah
Reviewed at:
Shark Ninja ANZ
Posted May 31, 2025
Terrible! Wasted money!
I got this airfryer for Mother's Day, and I couldn't be any more disappointed. I have used it half a dozen times, and no matter what I do the food doesn't cook. I have owned an airfryer (not a Ninja) for years and had no issues at all. My mum and my son both have the side by side version and are very happy with it. I now wish I had of purchased the same.
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Happy go lucky
Reviewed at:
sharkninja.com
Posted May 9, 2025
Perfect for Me
I’m very happy with this product because it’s just right for
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FooMan
Reviewed at:
sharkninja.com
Posted Apr 25, 2025
Definitely NOT TWO Airfryers
It's advertised as TWO airfryers. It is definitely NOT. It is one airfryer with two baskets. If you use 1 basket and cook Y amount of chicken it takes X time. Then when you cook using TWO baskets with total Y chicken in each basket, it take 2X time. That's as good as ONE airfryer if you ask me. Poorly worded marketing made me believe it would run two baskets in X time...
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Response from Staples :
Hello,
Thank you for taking the time to leave a review.
We're so sorry to hear that you aren't happy with
your Ninja . We will absolutely share your feedback
with the relevant teams for consideration on future
products. If you need any help with your product,
please don't hesitate to reach out to our team by
phone at 1-800-365-0135.
Kind regards,
Ninja Kitchen
April 28, 2025
Worst ninja product
Reviewed at:
sharkninja.com
Posted Apr 17, 2025
Save your money!
I was so excited to buy this… i am terribly disappointed. It takes forever to cook anything, the holes for venting in the back of the basket make it a mess! Crumbs, oil, and juice fly out the back… truly that’s enough to hate it but there’s more… if you leave a basket open or have to open it to take food out it completely kills the heat in the other basket… the space yo...
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Response from Staples :
Hello,
Thank you for taking the time to leave a review.
We're so sorry to hear that your Nina Air Fryer isn't working. We will absolutely share your feedback with the relevant teams for consideration on future products. If you need any help with your product, please don't hesitate to reach out to our team by
phone at 1-800-365-0135.
Kind regards,
Ninja Kitchen
April 23, 2025
coop74
Reviewed at:
sharkninja.com
Posted Apr 7, 2025
Missing Replacement Part Ruins a Great Product
I really wanted to love the Ninja Double Stack Air Fryer SL451. It’s compact, powerful, and comes with a smart thermometer feature that was the main reason I bought it. Unfortunately, I lost the thermometer—and that’s when the problems started.
Ninja does not sell a replacement thermometer for this model. That means if you lose it (or it stops working), the feature bec...
Ninja does not sell a replacement thermometer for this model. That means if you lose it (or it stops working), the feature bec...
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Response from Staples :
Hello,
Thank you for taking the time to leave a review.
We're so sorry to hear that you don't have the thermometer for your Ninja Air Fryer, as it was misplaced. Please reach out to our team by phone at 1-800-365-0135, we'd be happy to look into this for you.
Kind regards,
Ninja Kitchen
April 9, 2025
Bee75
Reviewed at:
sharkninja.com
Posted Apr 1, 2025
Does not stack up in my book.
This is the first time I officially have to say I am not happy with a ninja product. I bought this because I thought it would be a great space saver in my kitchen considering I don't have a lot of counter space. And I was super excited because I would be able to cook chicken wings in it all at one time instead of having to do batches of 8 to 10 at a time.
When I first...
When I first...
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Response from Staples :
Hello,
Thank you for taking the time to leave a review.
We're so sorry to hear that you were having trouble with your DoubleStack Air Fryer, and that you want to return the product as a result.
We will absolutely share your comments with the relevant teams for consideration on future products, and we hope you’ll give our products another try in the future.
If you need any further assistance with your product, please don’t hesitate to reach back out to our team at 1-800-365-0135.
Kind regards,
Ninja Kitchen
April 8, 2025