When comparing Code School vs CheckiO, the Slant community recommends Code School for most people. In the question“What are the best resources to learn Python?” Code School is ranked 11th while CheckiO is ranked 18th. The most important reason people chose Code School is:
After each video, there are a series of challenges that give you a chance to apply what you just learned. The great thing about these challenges are that they force you to think through a problem, and use the new skills to solve it. It's not just regurgitating facts; it requires some effort.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Practice the code after each video
After each video, there are a series of challenges that give you a chance to apply what you just learned. The great thing about these challenges are that they force you to think through a problem, and use the new skills to solve it. It's not just regurgitating facts; it requires some effort.
Pro Paths for learning different skills
While you can jump into any video you like, there is also the option to follow a path for what you are wanting to learn. These give a nice direction if you are wanting to improve on a particular area and guide you into what to do next. They currently offer Ruby, Javascript, HTML/CSS, and iOS.
Pro Videos show how to build an app in real time
Soup to Bits is a series of videos that shows a developer creating an app from scratch in real time. It's easy to pause a video and follow along with the developer.
Pro Video tutorials
Videos give an overview of the course/lesson plan before a single line of code is written. This gives context and a general understanding of what is possible and how teaching will be approached.
Pro Fun and engaging teaching style
The instructors often use humour throughout the videos while letting their passion for the topic show.
Pro In-depth courses
Code School is not just for beginners to programming, but provides plenty of intermediate and advanced courses for students as their skills grow.

Pro Community backed solution reviews
Users can publish their solutions for different problems and other users can review the code and give their opinions on how they would have solved the problem.
Sometimes, some of the most active users get their code reviewed by Guido Van Rossum (the creator of the Python language) himself.
Pro Available in multiple languages
CheckiO crowdsources translations for problems. Currently problems have been translated in 10 languages. So it's highly possible that eventually more languages will be supported.

Pro Ability to create new challenges
New missions can be created and uploaded using GitHub. After that is done, it's suggested to CheckiO and if it fills all the requirements after being reviewed by a CheckiO team member, it's pulled into the game.

Pro Challenges from GitHub, O'Reilly, Dropbox and Hubspot.
Cons
Con Acquired by Pluralsight
Con Videos are of a tone that some people cannot stand
Con Requires paying to complete courses
Although the beginning of each course is free and you can see if you are interested in pursuing it, to complete the course you must pay.
Con A bit too basic
There is not a lot of advanced content.
Con Not for absolute beginners
CheckiO does not teach syntax, instead it teaches how to solve problems using a particular programming language therefore some basic programming knowledge is required to start.
