The Ninja Blender Duo with Auto-iQ is a full-size blender with a versatile performance. It comes with three differently-sized personal jars in addition to its 72-ounce main jar. You can use it to make fantastic smoothies, incredible almond butter, and snow-like crushed ice. Its Auto-iQ feature allows it to detect what size of jar you're using, which changes what presets you can select. It's amazingly easy to clean either by hand or in your dishwasher, but unfortunately, it can't hot blend.
Our Verdict
The Ninja BL642 is good for multi-purpose use. It has a great build quality and a very versatile performance. You can use it to make fantastic almond butter, incredible smoothies, and snow-like crushed ice. The large-capacity main jar and three personal jars are all very easy to clean. However, you can't use it to blend hot ingredients.
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Makes fantastic smoothies.
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Various preset speeds and modes.
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Great build quality.
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Can't hot blend.
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Smoothies made in main jar aren't as good.
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Smoothies made in main jar aren't as good.
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Smoothies made in main jar aren't as good.
The Ninja BL642 is incredible for crushing ice. It has a great, sturdy build quality, and you can use the main jar to make snow-like crushed ice.
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Makes snow-like crushed ice.
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Great build quality.
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Smoothies made in main jar aren't as good.
The Ninja BL642 can't hot blend and isn't suitable for making soups.
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Smoothies made in main jar aren't as good.
The Ninja BL642 is fantastic for professional use. While it's entirely made of plastic, it has a great, sturdy build quality and its main jar has a large, 72-ounce capacity. You can use it to make smooth, spreadable almond butter, snow-like crushed ice, and incredible smoothies. It's really easy to clean, either by hand or in your dishwasher.
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Makes snow-like crushed ice.
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Makes smooth, spreadable almond butter.
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Main jar has a large capacity.
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Can't hot blend.
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Smoothies made in main jar aren't as good.
- 6.8 Multi-Purpose
- 8.8 Smoothies (Single Serving)
- 7.5 Smoothies (Multiple Servings)
- 9.7 Ice Crushing
- 4.7 Soups
- 7.3 Professional Use
- Updated Aug 25, 2022: The score for 'Fibrous Ingredients (Full Capacity)' changed from 5.6 to 7.2 because a longer blending time results in a better texture. The 'Texture' score changed from 5 to 6 and the 'Processing' score from 8 to 6.5 because of the extra time required.
- Updated Jul 28, 2022: Converted to Test Bench 1.0.
- Updated Apr 16, 2021: Review published.
- Updated Apr 13, 2021: Early access published.
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Differences Between Sizes And Variants
There are a few variants of the Ninja Blender Duo with Auto-iQ available. We tested the BL642 model, and you can see its label here. Depending on the model number, this blender can come with several differently-sized personal jars. As we tested the model that comes with all three differently-sized personal jars, we expect our results to be valid for the other models as well. However, depending on which one you have, some of our tests may have been performed using a jar that isn't included with your blender.
| Model Number | Details |
| 640 | Two personal jars (2x 24 oz) |
| 641 | Two personal jars (32oz and 24oz) |
| 642, 642W, 642W1 | Three personal jars (32oz, 24oz, 18oz) |
| 642Z | Three personal jars (32oz and 2x 24oz) |
If your model isn't listed here or you come across another variant, please let us know in the discussions so we can update our review.
Compared To Other Blenders
The Ninja Blender Duo with Auto-iQ BL642 has a similar look and design as other full-size Ninja blenders, such as the Ninja Professional Plus Kitchen System with Auto-iQ and the Ninja Professional Plus Blender with Auto-iQ. It performs better for most uses than those blenders, though, and is particularly well-suited for making single-serves because of its three differently-sized personal jars. Using the 32-ounce jar, it makes a better smoothie than most blenders that we've tested.
If you want to see more options, check out our lists of the best blenders for smoothies, the best blenders for crushing ice, and the best blenders for frozen drinks.
The Ninja Blender Duo with Auto-iQ BL642 is better for most purposes than the Ninja Nutri Ninja Auto-iQ. The Blender Duo has a significantly better build quality and comes with three differently-sized personal jars in addition to its 72-ounce main jar. It makes better-textured smoothies and crushed ice, as well as smoother, more spreadable almond butter. However, the Nutri is a much more compact personal blender.
The Ninja Blender Duo with Auto-iQ BL642 is better for most uses than the Ninja Professional Plus Kitchen System with Auto-iQ. The Duo makes much better smoothies and produces smoother, more spreadable almond butter. It also comes with three personal jars, while the Professional Plus Kitchen System comes with two. However, the Kitchen System also includes a food processing attachment, although we don't currently test it.
The Ninja Foodi Power Βlender & Processor System is more versatile than the Ninja Blender Duo with Auto-iQ BL642. The 642 has a sturdier build and is a better option for single-serve smoothies since it comes with three personal jars with to-go lids. However, it's not as good at processing big batches of fibrous ingredients. The Processor also comes with an additional jar that makes it easier to process thick recipes like nut butter, as well as a dough blade.
You may prefer either the Ninja Blender Duo with Auto-iQ BL642 or the Ninja Foodi Cold & Hot Blender, depending on what you're looking for. The Foodi can hot blend and heat ingredients. It's much better for processing big batches of fibrous ingredients like kale, so it's more suitable for recipes like soup. On the other hand, the Duo comes with three personal jars with resealable lids, so it's the better choice if you want to use your blender to make single-serve smoothies to-go.
The Ninja Blender Duo with Auto-iQ BL642 is better for most purposes than the NutriBullet Blender Combo. The Ninja has a better build quality. It can make snow-like crushed ice and is much better-suited for processing hard ingredients like nuts. All of its components are dishwasher-safe. On the other hand, you may prefer the NutriBullet because it can hot blend. It's much easier to clean by hand and is much better for processing big batches of fibrous ingredients like kale.
The Ninja Blender Duo with Auto-iQ BL642 and the Ninja Professional Plus Blender with Auto-iQ have a similar design and a similar performance in their 72-ounce main jars. Ηowever, the BL642 is better for making single-serve smoothies because it comes with three personal jars that you can use to make a silky blend with fibrous ingredients like kale. It's also somewhat quieter when it's running.
The Vitamix 5200 and the Ninja Blender Duo with Auto-iQ BL642 have different strengths, and you may prefer either one, depending on your needs. You can use the Vitamix blender for hot blending. Its main jar comes with a tamper and a two-part lid, and it has a significantly better build quality. In addition to its main jar, the Ninja has three differently-sized personal jars with matching to-go lids. It also makes crushed ice with a better texture.
The KitchenAid K400 is better than the Ninja Blender Duo with Auto-iQ BL642. The KitchenAid has a better build quality. It makes a smoother blend with fibrous ingredients like kale, especially when you're working with bigger batches, and it can hot blend. It's also easier to clean. On the other hand, the Ninja comes with personal jars and to-go lids for single-serve drinks like smoothies. It's also quieter when it's running.
The Vitamix Explorian E310 is a better full-size blender than the Ninja Blender Duo with Auto-iQ BL642. It's much better at processing ingredients like kale in its main jar. It's also easier to use for tough tasks like making nut butter. You can use it for hot blending and it's easier to clean by hand. On the other hand, you may prefer the Ninja because it comes with personal jars for blending single-serve smoothies. Its main pitcher has a bigger capacity and is a little better for ice-crushing.
The Ninja Mega Kitchen System BL770 is better than the Ninja Blender Duo with Auto-iQ BL642 for most uses. It makes a smoother blend with big batches of fibrous ingredients when you're making multiple servings of smoothies. It also comes with a food processing bowl. However, the BL642 comes with three personal jars for single-serve smoothies instead of two. Their to-go lids are resealable, so you might prefer that model if you plan to use the personal jars as travel cups.
The Vitamix A2300 and the Ninja Blender Duo with Auto-iQ BL642 have different strengths, and you may prefer either, depending on your needs. The Vitamix has a much better build quality and can be used to blend hot ingredients. It also comes with a tamper, has a greater number of speed settings, and takes less time to make smooth almond butter. On the other hand, the Ninja comes with three personal jars with to-go lids in addition to its main jar. It makes much better smoothies and crushed ice with a better texture.
The Ninja Blender Duo with Auto-iQ BL642 is better than the Ninja Foodi Power Pitcher System for most purposes. The Duo comes with more personal jars, and its 'Auto-iQ' feature allows it to detect what size of jar you're using. It also makes crushed ice with a better texture. On the other hand, the Foodi is much easier to clean.
The Ninja Blender Duo with Auto-iQ BL642 is better for most purposes than the Ninja DUO. The Blender Duo with Auto-iQ makes smoother, more spreadable almond butter and a silkier smoothie in its 32-ounce personal jar. It also makes crushed ice with a better texture. However, the DUO comes with more extra features, including a juicer attachment and a vacuum pump, although we don't test them currently.
The Vitamix A3500 is better for most purposes than the Ninja Blender Duo with Auto-iQ BL642. The Vitamix has a significantly better build quality. It's better at processing fibrous ingredients and making nut butter. You can also use it to hot blend. It's easier to clean by hand. Ηowever, the Ninja comes with smaller blending jars with resealable lids for making single-serve drinks like smoothies.
The Ninja Blender Duo with Auto-iQ BL642 is better than the Oster Pro 1200 for most purposes. The Ninja is better built, quieter, and comes with three personal jars for single-serves instead one. However, the Oster does a better job of processing big batches of fibrous ingredients in its main jar. Its design makes it easier to clean. Its jar is made of glass, which you might like better.
The Ninja Blender Duo with Auto-iQ BL642 and the Ninja Professional Plus Blender DUO with Auto-iQ are similar blenders. The BL642 comes with a 72-ounce pitcher and three personal jars for single-serve smoothies, and the DUO comes with the same 72-ounce pitcher and only one personal jar. It's also quieter when it's running. Otherwise, they perform about the same.
The Vitamix Explorian E520 is a better blender than the Ninja Blender Duo with Auto-iQ BL642. The Vitamix is studier, offers more speed settings, and it's easier to clean by hand. It's better for processing fibrous ingredients like kale and making nut butter. It can also hot blend. On the other hand, the Ninja comes with personal jars that you can use to blend single-serve smoothies. It's a bit easier to use to crush ice and it's quieter when it's running.
The Ninja Blender Duo with Auto-iQ BL642 is a better blender than the Blendtec Designer 725. The Ninja makes significantly better smoothies, much better almond butter, and comes with more additional jars. On the other hand, the Blendtec has a much better build quality. Also, while neither can blend hot ingredients, the Blendtec has a Hot Soup preset meant to warm up cold ingredients.
The Ninja Blender Duo with Auto-iQ BL642 is better than the KitchenAid Diamond. The Ninja has a much better build quality and makes significantly better-blended smoothies. It makes more spreadable almond butter, crushed ice with a better texture, and it's much easier to clean by hand. It also comes with three differently-sized personal jars in addition to its 72-ounce main pitcher. Nevertheless, you can use the KitchenAid Diamond to blend hot ingredients, so it's better for making soups.
The Ninja Blender Duo with Auto-iQ BL642 is better than the Ninja Foodi Power Pitcher SS201. The BL642 has a much better build quality, is easier to clean, makes snow-like crushed ice. It blends a silkier smoothie if you use its 32-ounce personal jar. However, the SS201 produces a much better smoothie in its 72-ounce main jar than the BL642 does in its main jar.
Test Results
The Ninja Blender Duo with Auto-iQ BL642 is a bulky full-size blender. It's best stored on your kitchen counter or in a large cupboard, and you can also remove the main jar for easier storage.
The Ninja BL642 has an impressive build quality. While the motor base and transmission are made completely of plastic, they don't feel flimsy. It's easy to dock and undock jars from the base, and there are bright blue LED lights to indicate what presets are available for the jar you're using. The blender won't run unless it detects that a jar is properly docked. The jars are made of good-quality plastic, but unfortunately, the suction cups under the motor base don't seem to grip onto surfaces very well. The mirrored accents on the front of the blender are prone to fingertip smudges as well.
The Ninja BL642's main blade assembly is similar to that of other Ninja blenders, such as the Ninja Mega Kitchen System BL770. It's shaped like a column with six sharp blades that spiral around it. There's also a second blade assembly for the personal jars. Both are top-rack dishwasher-safe.
The Ninja BL642's lid is made of plastic and has to be properly aligned to clip into place. There's a small window-like spout that can be used for pouring, but it's not a two-part lid and isn't intended for adding ingredients while blending.
The Ninja BL642's power cord should be long enough to reach an outlet near your counter. There's a place to wrap the cord on the back of the blender for easier storage.
- 72oz blender pitcher with lid
- Ninja BL642 motor base
- Stacked blade assembly
- 32oz jar
- 24oz jar
- 18oz jar
- Pro extractor blade assembly
- 3x to-go lids
- Manual
- Recipe book
The Ninja Blender Duo with Auto-iQ BL642 is fantastic for small batches of fibrous ingredients. Using its 18-ounce jar, it quickly makes an almost perfectly smooth puree with ingredients like kale.
The Ninja Blender Duo with Auto-iQ BL642 is mediocre for processing big batches of fibrous ingredients. If you fill the 72-ounce jar to its full capacity, it makes a grainy blend with ingredients like kale. It also takes nearly 10 minutes of blending to get the best possible results.
The Ninja BL642 is fantastic for crushing ice. It makes truly snow-like crushed ice very quickly.
The Ninja BL642 is fantastic for making almond butter. It has no issue processing the nuts if you start with 'Pulse' mode to crush them, then run the blender on low speed for roughly two minutes. When the mixture starts to develop a good consistency, blend on high for a few more minutes to finish the process. The result is very smooth, spreadable almond butter.
The Ninja BL642 comes with several preset speeds and modes. At maximum speed, it's quieter than the Ninja Mega Kitchen System BL770.
This blender is amazingly easy to clean. It's easy to rinse clean if you've been working with liquidy ingredients, and a quick blend with soap and warm water takes care of most stickier messes. The blade assembly is removable, which makes it easier and safer to clean out sticky food like almond butter, although you may need to occasionally use a brush to clean stubborn residue from the bottom of the jar. You should take care when cleaning the main jar by hand, though, as it has sharp edges around the rim where the lid fits into place. Luckily the main jar is also top-rack dishwasher-safe, along with all the lids, blade assemblies, and personal jars. If you're looking for a full-size blender that's easier to clean by hand, you may prefer the Breville the Fresh & Furious.
