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Instant Omni Plus 18L vs Mueller 4 Slice Toaster Oven Side-by-Side Comparison

Instant Omni Plus 18L vs Mueller 4 Slice Toaster Oven. A comparison between our best air fryer toaster oven and our best value small toaster oven.

Instant Omni Plus 18L vs Mueller 4 Slice Toaster Oven


Price at publication
L16.54 x W15.75 x H13.90 inchesL14.96 x W11.61 x H8.86 inches
25.4 lbs (11.5 kg)9.0 lbs (4.1 kg)
Control Type
black LCD digital touchscreen + one master-control knob3 control knobs
150°F - 450°F150°F - 450°F
1 - 60 minutes1 minute - 30 minutes + stay-on
Cooking Functions
Interior Dimensions
L13.77 x W12.59 x H8.66 inchesL10.62 x W9.84 x H7.48 inches
24.6 liters12.81 liters
Heating Elements
4 quartz and 1 nichrome2 quartz
Convection Fan


Build Quality
Overall Design Scoring

The design of the Instant Omni Plus 18L 140-4002-01 Air Fryer Toaster Oven shows attention to detail and makes use of modern technology, which resembles the larger Ninja DT201 a lot. While not perfect, its strong points are more than enough to make up for the minor drawbacks.

Stood out to us were the combination of one nichrome and four quartz heating elements as well as the oven’s powerful convection settings. However, the spacing between the four rack levels made it difficult to place a baking pan to catch drippings while roasting a whole chicken with the rotisserie kit.

The Mueller has a standard design for a small oven which further highlights its detachable crumb tray. Its quartz heating elements can be another factor worth considering if you’re into energy efficiency.

Usability Comparison

User Control
Ease of Use
Overall Usability Scoring

The Instant Omni Plus 18L 140-4002-01 Air Fryer Toaster Oven is the opposite of a simplistic analog unit like the Cuisinart TOA-60. It maximizes its ease of use but that leads to some weak points in and of itself; the same goes for its user control.

The oven’s touchscreen LCD is very easy to operate with all of its separate cooking functions and feature toggles despite having only one master-control knob and a subpar color contrast. Due to insufficient space, however, the cooking chamber can get quite tricky to clean in case of big greasy messes.

Similar to most small toaster ovens, the Mueller is easy to operate but not the most convenient to use. For instance, the control panel has a lot of room for errors and the oven’s interior doesn’t have a non-stick coating for easy cleaning.

Performance Test

Whole Roasted Chicken
Baked French Fries
Overall Performance Scoring

The performance of the Instant Omni Plus 18L 140-4002-01 Air Fryer Toaster Oven is consistently great. In particular, it’s excellent at baking/ air frying fries and roasting a whole chicken. This is thanks to its great design, strong convection system as well as useful accessories—including an air fryer basket and rotisserie kit.

The Mueller showed its strength in heat distribution with its score in toasting bread, baking pizza, and roasting a whole chicken. However, baking french fries showed its weakness of low power draw which is common in small toaster ovens.

Overall Scores

Overall Scoring

Pros & Cons

  • Informative and eye-catching package
  • Smart Programs and cooking status bar
  • Electrical safety feature for the door
  • Convenient slide-out crumb tray
  • Safeguards for all heating elements
  • Complimentary app with detailed instructions and numerous recipes
  • Helpful toggles
  • Easy-to-clean stainless steel exterior
  • Lightweight and small size
  • Easy-to-clean stainless steel exterior
  • Cool-touch door handle
  • Simple control knobs
  • Stay-on feature
  • Quartz heating elements have safeguards
  • Energy-saving
  • Touchscreen digital displays need more contrast
  • The master-control knob can be confusing
  • No convection fan
  • No internal lighting
  • No safety mechanism for the door


Between the Instant Omni Plus 18L Air Fryer Toaster Oven and the Mueller 4 Slice Toaster Oven (MT-175), the first one is without a doubt the winner. Nonetheless, they still bring up interesting points of comparison as our best air fryer toaster oven and our best value small toaster oven respectively.

Design and usability-wise, the Mueller doesn’t offer much besides its detachable crumb tray for cleaning the inside. Meanwhile, the Instant has an LCD touchscreen with smart programs, audio cues, toggles, and cooking presets. The oven’s also equipped with a slide-out crumb tray, interior light, and tray-level indicators on the glass door.

Even though the Mueller couldn’t compete with a true powerhouse like the Omni Plus 18L in terms of performance, it still put up a good fight, especially for a small unit.

The Mueller was able to keep up with the Omni Plus in toasting bread, which was great. However, even though its results in baking pizza and roasting whole chicken were good, the Instant’s were exceptional.

Most importantly, the Mueller still has the common weakness in baking fries like many same-sized units whereas this test was the one where the Omni Plus excelled, even among all of our best picks.

Behind the Comparison

Headshot of Alan Nguyen
Alan NguyenReviewer

Alan Nguyen is a writer and product reviewer at HealthyKitchen101. His major in English language teaching taught him to present concise information. In addition to his cooking hobby, he values the practical aspects of household appliances.

Headshot of Tuyet Pham
Tuyet PhamProfessional Chef

Tuyet Pham is an award-winning Saigonese chef passionate about delicious and healthful foods. At HealthyKitchen101, she develops recipes and collaborates with our Research, Testing, and Review lab to evaluate the performance of cooking appliances. Her assessments add a strong authoritative voice to our product scoring process.

Headshot of Lap Vo
Lap VoTest Lead

Lap is Head of the Research, Testing, and Review Team (RTR Team) at HealthyKitchen101.com, where he directs and supervises the testing of kitchen gadgets and appliances.

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