Kotlin vs Java: Which is better in 2023?

Kotlin vs Java: Which is better in 2023?

As a developer, you must constantly decide which programming language to use for your next project.

In the case of Android development, two of the most popular options are Java and Kotlin. Both are powerful, making it difficult to choose one.

In this blog, we will dive into their differences and explore their syntax, job demands, applications, features, and more.

So, continue reading this blog to understand the perfect language for your project.

Java vs. Kotlin: Overview

Java is a popular programming language that was first released in 1995 and is widely used for building many applications, including web, mobile, and desktop applications.

It is a general-purpose programming language known for its readability, simplicity, and portability, as well as its vast ecosystem of libraries and frameworks.

On the other hand, Kotlin is a relatively newer programming language that was first released in 2011. It is a statically typed programming language fully interoperable with Java, meaning you can use Kotlin code in a Java project and vice versa.

Kotlin is known for its concise and expressive syntax, making writing and maintaining code easy.

Java vs. Kotlin: Application

Both Kotlin and Java have their application areas. Here are some general guidelines for when to use Kotlin and when to use Java:

When to use Kotlin?

You can use Kotlin if you prefer a more concise and expressive syntax that is easy to understand. Kotlin has several features that make it more powerful and efficient than Java, such as improved type inference, higher-order, and extension functions.

Use Kotlin if you want to build:

  • Android Apps
  • Data Science Projects
  • Coss-Platforms Applications (including desktop apps)

When to use Java?

You must use Java for large legacy codebases in a professional development environment. Most old databases are also written in Java, so you need to use it to maintain them.

In addition, you can use java to build:

  • Android Apps
  • Web Apps
  • Embedded Systems
  • Scientific Computing Systems
  • Desktop Apps

Java vs. Kotlin: Job Demands

According to data from Indeed, Java is currently the most in-demand programming language, with over 81,000 job openings in the United States alone.

Kotlin is a newer programming language that has recently gained popularity, particularly in Android development. While it is not as widely used as Java, it is gaining traction in the job market and is increasingly being adopted by companies for Android development.

In terms of salary, Java developers tend to earn higher wages than Kotlin developers. However, the exact figures can vary depending on the developer's location, industry, and experience level.

According to data from Glassdoor, the median salary for a Java developer in the United States is around $95K per year, while the median salary for a Kotlin developer is $105K per year.


Job Demands








Java vs. Kotlin: Difficulty

In terms of difficulty, Java and Kotlin are relatively similar. Both languages have a steep learning curve, especially for people new to programming.

However, Kotlin is generally considered easier to learn and use than Java, especially for developers familiar with other programming languages.

In terms of Syntax, Kotlin is more concise and expressive. Take a look at the simple "Hello, World!" program in the two languages and compare the difficulty for yourself:


public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
"Hello, World!" in Java


fun main(args: Array<String>) {
println("Hello, World!")
"Hello, World!" in Kotlin

As you can see, the Kotlin code is shorter and simpler than the equivalent Java code. This is one of the main reasons why Kotlin is often considered easier to use than Java.

Java vs. Kotlin: Performance

Kotlin code performs slightly better than Java code because Kotlin is a modern language designed for better code efficiency.

In addition, Kotlin has several features, like type inference and inline functions, to help improve code performance. It is easier to read and maintain Kotlin code, so it has a more concise syntax that makes the code less prone to errors.

However, the actual difference in performance is relatively minute in real-life uses. Factors such as code design and optimization can impact performance more, no matter the language.

Advantages and Disadvantages of Kotlin and Java

Both Kotlin and Java have their pros and cons. So, knowing what language is best for a certain situation is important.

With that in mind, let us now take a look at some pros and cons of these two languages.

Advantages of Learning Kotlin Over Java

  1. Kotlin is more concise and expressive than Java, meaning fewer code errors.
  2. Unlike Java, Kotlin is modern, with extra features such as inline functions and type inference to make your code readable.
  3. You can use Kotlin with java in the same project, which makes it easier to mitigate existing Java code to Kotlin.
  4. Kotlin supports functional programming concepts like lambda expressions and higher-order functions.
  5. Kotlin has better support for Android development than Java, with better Android Studio integration and better support for Android app development tools.

Advantages of Learning Java Over Kotlin

  1. Java is a more established programming language than Kotlin. So, more resources are available for learning and more job opportunities for Java developers.
  2. Java has a comparatively large developer community and a long development history, which means that more libraries and frameworks are available for Java than for Kotlin.
  3. Java has a wide range of uses that goes beyond Android App Development.
  4. Java already has many resources online that you can use to learn. We can't say the same for Kotlin.

If you want to give Java a try, why not take our Learn Java course?  

Java vs. Kotlin: Comparison Table



Kotlin's syntax is more concise and expressive than java's. 

Java has a more verbose and explicit, traditional style syntax

Kotlin is fully interoperable with Java, i.e., we can use Java code in Kotlin. 

We cannot use Kotlin code in Java. 

Kotlin has better support for functional programming like lambda expressions and higher-order functions. 

Java's support for functional programming is limited. 

Since it is a new language, Kotlin features better Android studio integration and supports Android development tools. 

Java is still widely used for android app development, but it lacks many new Kotlin features. 

Kotlin has a growing community of developers, but the number is a bit smaller than in Java. 

Java has a bit larger and more established community of developers. 

Kotlin has a niche job market, as most Kotlin development jobs are focused on android development.

Java has a pretty vast job market that covers android development, systems engineering, database management, and other career options. 

Frequently Asked Questions

1. Is Kotlin replacing Java?

No, Kotlin is not replacing Java. Instead, it is a Java alternative that developers can use to build Android apps. Many developers prefer Kotlin due to its concise syntax and improved functionality compared to Java.

2. Is Kotlin harder than Java?

It is difficult to compare Kotlin and Java in terms of difficulty because both languages are somewhat similar.

Kotlin is a statically typed language, meaning the variable type must be known at compile time. This can be beneficial for catching errors early on, but can also be more difficult to understand than dynamically typed languages.

On the other hand, Kotlin has features such as type inference and data classes that can make it more concise and easier to read than Java.

3. Is Kotlin better than Java in 2022?

Kotlin has recently gained much popularity and is the recommended language for Android app development.

It is considered a more modern and powerful language than Java, with features such as improved type inference and support for functional programming.

However, Java is still a widely used and respected programming language, and the choice between Kotlin and Java will depend on the preference of the developer.

4. Is Kotlin worth learning in 2022?

If you are interested in Android app development or want to learn a modern programming language, then it will be a good idea to learn Kotlin. If not, then there is no point.