Updated December 2021
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Buying guide for best k’nex sets

K’NEX sets are so much more than toys. Introduced in 1992, the unique building system allows aspiring architects to connect plastic rods, blocks, wheels, rotors, tracks, and other components together, constructing either pre-designed structures or unique creations. While they’re fun on their own, K’NEX Sets are also renowned learning tools for kids, so much so that they are often used in classrooms to teach science, technology, engineering, and math principles.

K’NEX sets help kids sharpen their fine motor skills as well as their focus and patience. They’re also effective at increasing kids’ problem-solving skills. Which sets are our favorites? Read our complete buying guide to find out.

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Between ages five and seven, children are able to follow basic instruction manuals on their own and build more complex structures independently. Some kids will want to collect K’NEX sets inspired by their favorite TV shows, movies, or comic books.

Key considerations

Set size

The possibilities are nearly endless when it comes to K’NEX, but an easy way to narrow down your purchasing decision is by looking at the number of pieces a set has. Larger sets typically cost more, of course, but they also allow for multiple creations out of the same box. So while it may be tempting to buy a single-model set for around $10, you might want to consider a larger, more intricate set that offers more end results and more chances to learn.


With larger size comes an increase in difficulty, which is usually designated by the age range recommendation. There’s more to it than that, however, as difficult models include moving parts, pistons, gears, and delicate pieces to create ornate machines. These machines can range from simple windmills and swings to moving vehicles, roller coasters, and even motorized sets.

K’NEX set features

Storage tubs

The hardest part about K’NEX often isn’t the building process, it’s finding every piece you need beforehand and cleaning them up after. To make the process easier, some K’NEX sets include storage boxes to keep everything in the right place. These cases vary — some look like mini suitcases and some like basic tubs — but they’re worth their weight in gold if you have multiple sets.


One thing that separates K’NEX sets from LEGOs is the quantity of moving parts. While many LEGOs do feature moving pieces, K’NEX are on another level when it comes to interactive machines like cars, aircraft, and even amusement park rides.

A large portion of K’NEX sets don’t use motors at all, instead relying on hand-cranked gears and levers, but certain iterations do use battery power. These are typically designed for older kids. They allow for hands-off operation and can take the experience to the next level.

App connectivity

K’NEX offers two apps to enhance the constructing and overall learning experience. The first is the K’NEX 3D app, which allows you to browse 3D images of every set available. This can help with troubleshooting and can jumpstart the creative process by providing an up-close look at the company’s current models. Having trouble finishing that four-story high-rise? Boot up the app to take a closer look.

In addition, the K’NEX Ride It! app gives you the opportunity to “ride” K’NEX roller coasters in 2D and even VR, giving children a new way to enjoy their handiwork after they’re done.

K’NEX set prices

The majority of K’NEX sets contain simple plastics and basic electronics, but given the brand’s long history, there’s more variance in their catalog than you might think. At the low end, you can find non-motorized building sets for less than $10. These include straightforward environments and creatures and are generally geared toward ages three and up. You can get your hands on small-scale battery-operated units for around $15, though.

Mid-range K’NEX sets cost between $25 and $50 and offer complex motorized designs as well as multi-model building sets with several hundred pieces or more.

At the top of the range, you’ll encounter K’NEX sets with thousands of pieces costing well over $100. These can be used construct complex bridges, roller coasters with moving parts, and various intricate machines that use batteries and motors.

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Did you know?
The largest K’NEX model ever made was built in 2012 by Space Camp crew trainers. Affectionately named K’REX, the life-size tyrannosaurus rex contains 160,000 pieces and measures 12.46 feet high, 33.76 feet long, and 5.93 feet wide. It weighs 10 pounds.


  • K’NEX piece are made from ABS and POM plastics and can be easily cleaned with soap and water. However, be sure to keep water away from all motors, batteries, sound modules, and other electronics.
  • K’NEX parts are 100% recyclable, so if you no longer have use for them, don’t throw them in the trash. Better yet, hold on to them and gift them to another child.
  • If your child is new to building and basic mechanical concepts, start small. You don’t want to overwhelm and frustrate a growing mind, as this could turn them off to the concept altogether. Recommended projects for newcomers include boxes, swings, and basic houses.
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Micro K'NEX sets are, as the name implies, smaller versions of classic K’NEX sets. To help you differentiate the two, they never use the same color for corresponding pieces. For example, a Micro K’NEX three connector is yellow, while a standard K’NEX three connector is red.


Q. What’s are the main differences between LEGO and K’NEX?
LEGOs are a classic toy that can be used to jog the creative interests of young children. LEGOs are generally simpler, with an array of hard blocks forming solid structures that feature fewer moving parts than K’NEX. This makes K’NEX the superior option for teaching engineering and mechanical principles. However, LEGOs are far more durable and are more closely tied with pop culture trends.

Q. What is the best age to introduce my kids to K’NEX?
K’NEX recommends you introduce your kids to building sets between the ages of three and five. At these ages, children require less supervision but have flourishing imaginations. Sets designed for this age group include large, easy-to-handle pieces with bright, fun colors.

Q. What are K’NEX Education sets?
K’NEX Education sets are designed with the classroom in mind. They can be integrated into existing curriculum to help visualize engineering, mathematics, and physics principles, and in some cases, they include comprehensive lessons that can even replace existing curriculum. One example is Simple Machines Deluxe, which divides a classroom into five groups, each of which focuses on a different type of machine. When all the groups have completed their lesson, they present their findings to the rest of the class.

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