5 Free Online Courses to Learn Kotlin in 2025 - Best of Lot

Hello guys, If you are in Android application development or server-side Java development, then you might have heard about the Kotlin programming language, created by JetBrains, the company behind popular IDEs like IntelliJIDEA, PyCharm, and WebStorm. Kotlin is also Google's official language for developing Android apps. If you don't know what Kotlin is and why you should learn Kotlin, then let me tell you that Kotlin is a mature programming language that offers many benefits over traditional programming languages like Java which has been time-tested over the last 25 years. Kotlin is designed to solve pain points of Java programming language like verbose nature and boilerplate.

Kotlin has been around for quite some time now, but it really took off since 2017 when Google chose it as the official programming language for developing Android apps. That brings a lot of interest from both Java and Android developers to learn Kotlin, and why not? It's fully compatible with Java, and what you can do in Java in 20 lines is that in 5 lines in Kotlin.

In fact, I have been recommending Java developers to learn Kotlin and have shared some books and courses to learn Koltin as well, which was liked by many of you, but there was also a request to share more free resources like books, tutorials, and courses.

Earlier, I shared the best courses to learn Kotlin in 2025, and today, in this article, I will share some of the best free online courses to learn Kotlin in 2025.

I have collected these courses from different websites online like Udemy, Pluralsight, Coursera, and it even has a lesson from Google for learning Kotlin for absolutely FREE.

You can use these courses to learn Kotlin programming language, basic and advanced concepts, and server-side Java development alongside Java and creating Android apps where Kotlin really sees a lot of traction.

Btw, If you don't mind paying a few bucks for learning a valuable skill like Kotlin, then I highly recommend you check out Kotlin for Java Developer course on Udemy, which is both comprehensive and very engaging. You can use this course to learn Kotlin for server-side Java development and mobile app development with the Android platform.

5 Best Free Online Kotlin Courses for Beginners in 2025

Without wasting any more of your time, here is my list of the best free courses to learn Kotlin basics for Java and Android developers. These free courses are from Udemy, Pluralsight, and Coursera, a few best online training platforms.

Don't think that because they are free means they are of inferior quality. They are made accessible by their instructors for educational and marketing purposes, and they are actually top-quality online training courses.

1. Kotlin Programming - A Basic Introduction [Udemy Free Course]

This is the best free course to learn Kotlin online and also on Udemy. Created by  Ricky Wahowa, this 1 hour long free course will teach you basic concepts of Kotlin you need to start programming with Kotlin. 

This course is suitable for both Android and Java developers or anyone who wants to learn Kotlin  for Android app development or backend development in 2025.

You will learn the following things in a short but focused Kotlin course
1. Introduction to the Kotlin programming language

2. How to install Kotlin on your machine
2. How to create your first Kotlin Program and Variables
3. Kotlin syntax and Types in kotlin
4. Control Flow, Conditions
5. Ranges
6. Looping: for, while repeat loops
7. Functions
8. Closures, Lambdas, Higher-order functions

After finishing this course, you will have solid fundamentals of what is Kotlin is and how to use it in server side development, Android development, and anywhere else where kotlin supports

Talking about social proof, this course has on average 4.5 ratings, and more than 340 students have enrolled in this course which speaks a lot about the quality of this free course. If you are looking for a free class to learn Kotlin in 2025, I highly recommend joining this course.

2. Kotlin for Java Developers on Coursera [Free to Audit]

This is another awesome course to learn Kotlin Programming language for both App development and  backend development in 2025. This course is created by none other than JetBrains, creator of Kotlin Programming language. This is in fact the most popular Coursera course to learn Kotlin.

This course is created for Java developers who wants to learn Kotlin programming language but its also suitable for anyone who wants to learn Kotlin but only if you have experience with other programming language.

Note that this course doesn't cover the programming fundamentals but it discuss basic syntax, nullability, functional programming with Kotlin, object-oriented programming with Kotlin, the power of the Kotlin standard library, and Java interoperability. You can audit this course for FREE on Coursera. 

By the way, If you are planning to join multiple Coursera courses or specializations, then consider taking a Coursera Plus subscription which provides you unlimited access to their most popular courses, specialization, professional certificate, and guided projects. It costs around $59/ per month but is worth it because you get access to more than 7000+ courses and projects, and you can also get unlimited certificates.

3. One-hour Kotlin guide for beginners [Udemy Free Course]

This is one of the best free course to learn Kotlin for both Java and Android developers on Udemy. Created by Tutlets Kkang this is a compact and quick Kotlin guide from Kotlin essential to OOP programming.

The course contains almost 1 and a half hours of content to learn Object-Oriented Programming with Kotlin, and you will learn the following things in this course:

• Kotlin Basic
• Kotlin file Structure & Package
• Data Type and Variable
• Array, List, Map, Iterator
• Function
• Loop and Conditional Expression
• Property and Null Safety
• Late init, lazy
• Kotlin OOP Programming

After completing this free Kotlin course, you should have a good knowledge of how to write code in Kotlin and use its object-oriented programming features. Talking about the social proof, this course has on average 4.2 ratings out of 5, and more than 6000 students have enrolled in this course which shows a lot about the usefulness.

4. Kotlin Bootcamp for Programmers By Google  [CodeLabs Google]

This is a bootcamp course to learn Kotlin for both Java and Android developers. None of this course is provided by Google, which owns the Android platform and the company behind Flutter, Golang, Angular, Dart, TensorFlow, and Google Cloud.

In this course, you will learn the basics of Kotlin and the benefits of using Kotlin over Java as you will write many small programs in IntelliJ IDEA, one of the best IDE for Java and Kotlin developers and developed by JetBrains, creator of Kotlin programming language.

This course is provided by Google Developers Codelabs, which provides a guided, tutorial, hands-on coding experience. Most codelabs will step you through building a small application or adding a new feature to an existing application.

This course is also a prerequisite for the Android Kotlin Fundamentals course, another free course by Google to learn Android app development using Kotlin. The Android Kotlin Fundamentals course was created by the Google Developers Training team. In the study, you learn Android Kotlin programming concepts and build a variety of apps.

5. Mastering Kotlin: a Fast Guide to Null Safety (in 30 min)  [Udemy Free Course]

This is a concise course to learn how Kotlin provides Null safety, a significant problem for Java developers for the last 25 years. Created by Skill Centric, this course offers valuable information about the Kotlin type system in 30 minutes.

You will learn the following things in a short but focused Kotlin course.

1. Differences between the Java and Kotlin type systems.
2. Learn how Kotlin will help you handle the notorious NullPointerException at compile time rather than runtime.
3. Differences between nullable, not null, and platform types.
4. Safe the call operator
5. The Elvis operator

After completing this course, you will be very comfortable with Kotlin nullability, which is one of the language's main advantages and core features. You will also learn the safe cast operator, the not-null assertion, the let function, and other essential techniques for working with nullable types in the Kotlin programming language. Overall an excellent free course to learn the Null safety features of Kotlin.

6. Getting Started with Kotlin by Kevin Jones [Pluralsight Free Trial]

This course aims to give you an introduction to Kotlin to get you to develop applications quickly. It's also a practical and hands-on course and great for Java and Android developers who want to use Kotlin for Server-side and Android app development.

You will learn the following things in this course
1. How to install the Kotlin tools and set up the IDEs to use Kotlin
2. How to use the object-oriented features of Kotlin
3. how to use the programming features of Kotlin
4. how to write and run tests in Kotlin

After completing this course, you'll have a strong foundation of knowledge of the basic syntax and features of Kotlin.

Btw, you would need a Pluralsight membership to access this course. If you don't have Pluralsight membership, you can also take advantage of their 10-day free trial to access this course for FREE, as their free trial provides 200 minutes of free access to all of their 5000+ latest online training courses, including Kotlin and Java.

7.  Web Development with Kotlin [Free]

If you are looking for a free course where you can learn how to build Microservices, REST ,and GraphQL web service, both client and server then this free Kotlin course on Udemy is perfect for you. Created by Alexy Soshi, this 1 hour 39 minutes long course will teach you Kotlin for web development in 2025.

Here are key things you will learn in this free Kotlin course:

• Kotlin Basaics
• Ktor Web Framework for web development with Kotlin
• how to deploy Microservices on Heroku cloud platform
• how to test Kotlin programs and applications
• how to build GraphQL client using Kotlin
• Dependency management using Gradle
• how to run Kotlin inside Docker

The best thing about this free Kotlin course is that its a project based and you will learn by doing. You will  build a microservice using Kotlin programming language and Ktor framework, then deploy it to Heroku, a free service to deploy your app on cloud. The microservice will feature a cat hostel. You'll be able to add new cats, remove and list them.

That's all about some of the best free courses to learn Kotlin Programming language. As Java is almost 25 years old and hasn't changed much, Kotlin is like a modern version of Java and addresses many of its shortcomings like verbosity. You can learn Kotlin not just for Android app development but also for backend development. A lot of Java developers are learning Kotlin for backend development in 2025. 

It also offers a nice balance of goodness of both OOP and Functional programming, making it a great programming language and worth learning in 2025. And, if you want to learn Kotlin in 2025, these free online training courses will certainly help you.

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Thanks for reading this article so far. If you like these best free Kotlin online training courses and find them helpful, please share them with your friends and colleagues. If you have any questions or feedback, then please drop a note.

P. S. - If you don't mind paying a few bucks for learning a valuable skill like Kotlin, then I highly recommend you check out these best Kotlin courses from Udemy, which are both comprehensive and very engaging. You can use this course to learn Kotlin for server-side Java development and mobile app development with the Android platform.