Lego vs K’Nex – What are the Differences?

Toy products

Constructions toys are among some of the best educational tools on the market today. These sets should be carefully selected to pick the one that offers a combination of enjoyment, versatility, and value for money. Here we have reviewed Lego vs K’Nex construction toys to help you choose the best. Needless to say, these are super popular brands (for a reason).

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What are Lego and K’Nex and why you should consider them

 Lego and K’Nex are building and construction toy systems. Using plastic bricks and other accessories, kids can play and construct creative structures by interlocking the building blocks. Kids can build intricate and real designs that help them in Science, Technology, Engineering, and Mathematics (STEM) development. You should consider buying these systems if you want your kid to learn something new while at the same time having fun while playing. I grew up on  Lego but I’m a curious person and therefore I dug into the world of K’Nex to find out what’s special about these.

Is K’Nex Compatible with Lego?

K’Nex does produce bricks that fit the Lego bricks. This compatibility allows you to connect these two construction systems, make structures with K’Nex, and play around it with Lego vehicles.

Lego vs K’Nex – Similarities and Differences

Material Quality

Both use quality material that can last for long; however, Lego toys are more durable than K’Nex.


Overall, K’Nex is very good for creating complex and intricate designs compared to Lego designs. If your kid enjoys more complicated ideas, K’Nex may be the best option for them because of the intricate design they offer. This video shows the benefits of playing with Lego.


The more realistic the toy is, the more your kid will be able to extract knowledge from it. Both Lego and K’Nex toys exhibit reality in the real-world, making kids’ playtime more fun and enjoyable.


Both Lego and K’Nex uses non-toxic material to make their toys kid-friendly.


Both Lego and K’Nex toys are lightweight for kids to carry and play with wherever they want. However, Lego’s products are a bit heavier than those of K’Nex.


K’Nex is much cheaper than Lego building toys.

Lego vs K’Nex – which one to choose?

Your choice of the best building toy will depend on the age of your child and the above factors. Generally, if you are looking for a building toy set that will not break your bank account and, at the same time, ensure that you get durable, realistic, and sophisticated designs, you might consider taking the K’Nex path.

K’NEX Imagine – Power and Play Motorized Building Set

The creative and play opportunities are almost endless with this set. K’Nex Imagine is a brilliant construction toy set that uses rods, connectors, and wheels to make creative models. K’Nex imagine set comes with a battery-powered motor to add motorized motions to models.

Product Information

  • Size: 18.5*4*14 inches
  • Weight: 3 pounds
  • Pieces: 529
  • Recommended age: 7 years and up

Why you should consider it

  • Easy to use – power and play motorized building set is easy to use, and it comes with clear, easy-to-follow instructions to create an endless array of models
  • Colorful pieces – all pieces are color-coded with vibrant colors making it fun to play with


  • Non-toxic material
  • Lightweight
  • Convenient packaging
  • Durable
  • Easy-to-follow instructions
  • Helps with STEAM development


  • Motor requires batteries
  • Not suitable for children under 7 years old.
  • Small parts can easily get misplaced or swallowed by kids.

Highly adaptable – K’NEX 70 Model Building Set

With the K’Nex Model Building Set, you can construct any model you can imagine from animals, trucks, planes, amusement parks, and many more. Both boys and girls can use the set as each gender can construct things that interest them the most. With 705 classic pieces, you will be able to create unique models that actually move.

Product Information

  • Size: 16*7.8*10.5 inches
  • Weight: 3.3 pounds
  • Pieces: 705
  • Recommended age: 7-15 years

Why you should consider it

  • Step-by-step Instructions – the set comes with pre-suggested projects and instructions to get you started right away.
  • Handy storage box – The package comes with a classic storage box to keep the very many pieces in one place and organized.


  • Promotes STEM learning
  • Highly versatile
  • Long-lasting pieces
  • Non-toxic material
  • Brightly colored pieces
  • Easy to clean


  • Very many small parts can get lost easily

Best for learning – K’NEX Education ‒ STEM Explorations: Roller Coaster Building Set

Further your child’s understanding of STEM concepts with the fun and engaging K’Nex Education Building set. It comes with 546 pieces to build the roller coaster, ramp, half-pipe, battery-powered motor, coaster car, and instruction guide.

Product Information

  • Size: 12.5*12.2*2.2 inches
  • Weight: 1.92 pounds
  • Pieces: 546
  • Recommended age: 8 years and up

Why you should consider it

  • Vibrant colors – the pieces have different colors, which inspires more play and creativity
  • Pre-build experiments – The set comes with 3-after build experiments to teach your child about STEM concepts and more


  • Easy to clean
  • Reliable set to last long
  • Lightweight
  • Safe for kids use
  • It teaches STEM


  • The motor requires batteries to run
  • Age restrictions

Most expensive – LEGO Boost Creative Toolbox 17101 Fun Robot Building Set

Build up to five different robots with LEGO Boost Robot Building Set. The set comes with a whopping 847 different Lego bricks, motor, light sensor, and the move hub, two built-in engines that serve as the central processing unit for the robot. It also provides an entraining app that turns learning into a game that even preliterate children can master.

Product Information

  • Size: 21.3*11.1*3.6 inches
  • Weight: 4.2 pounds
  • Pieces: 847
  • Recommended age: 7 – 12 years

Why you should consider it

  • It comes with an app – the Lego understands how young children learn and has designed the perfect interface for them. This app strikes a balance between simplicity, depth, and fun.


  • Intuitive and engaging software
  • Simple projects
  • Clear instructions
  • High-quality set
  • Colorful bricks


  • Based on programming language making it hard to use
  • Age restrictions to 7 years and up
  • Expensive

Most durable – LEGO Ideas NASA Apollo Saturn V 21309 Outer Space Model Rocket

Explore the universe by inspiring and building the next generation of astronauts with the LEGO Space Model Rocket. The set comes with everything you need to create a space rocket and role play Saturn V mission at the same time having lots of fun.

Product Information

  • Size: 14.9*18.9*4.4 inches
  • Weight: 7.5 pounds
  • Pieces: 1969
  • Recommended age: 14 years and up

Why you should consider it

It has a realistic design – the spaceship measures over 100cm high and 17 cm in diameter, making it the model huge and real like the exact rocket.


  • Durable
  • Portable
  • Non-toxic Material
  • Detailed instruction booklet


  • Expensive
  • Not suitable for kids under 14years


The bottom line is, both K’Nex and Lego are great building bricks for kids, so your decision will have to fall on the features you need. If your kiddo needs something more complicated and intricate to build, Knex may be your best bet. If you are looking for a lightweight and affordable option, K’Nex is also your best option. If durability is, however, what you need, Lego may be better for you. Lego is heavier, but it’s also more durable.

Another comparison that I thought mentioning is LEGO vs Mega Construx, since the latter is a major brand, too.

Last update on 2024-06-16 / Affiliate links / Images from Amazon Product Advertising API

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