Kotlin vs. Java - Which One to Choose for Your Next App?by@pixelcrayons
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Kotlin vs. Java - Which One to Choose for Your Next App?

by PixelCrayonsOctober 25th, 2021
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Java has been around since 1995, and it's still the most popular programming language in the world. Kotlin offers several advantages over Java, including faster compilation times, more elegant syntax, and better type inference. As per Statista Survey 2020, Kotlin has a **popularity of 8.32% among developers** worldwide, while Java is preferable to 49% of developers**. It eases interoperability between other languages and allows other coders to work with your code more efficiently, improving team efficiency.

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Java has been around since 1995, and it's still the most popular programming language in the world. It means that most job positions are available as Java developers or something similar. But there's also Kotlin, released by Google in 2016 & has quickly become one of the most popular languages of all time among software developers. In this blog, we are going to discuss Kotlin vs. Java.

Kotlin offers several advantages over Java, including faster compilation times, more elegant syntax, and better type inference. Kotlin and Java are both object-oriented programming languages that run on the JVM and use a lot of related frameworks and APIs.

Because of their similarities, it's easy to learn Kotlin if you already know Java and vice versa. The syntaxes are so similar that most people can pick up Kotlin by reading through code samples and taking a couple of hours to code.

As per Statista, Kotlin is preferable to 14% of software developers worldwide in 2021, while Java is preferable to 49% of developers. However, is a developers' survey enough to decide the best between the two?

Well, the answer is an obvious no. True, it offers excellent insights into developers' choices, but there's more to explore when finding the ideal programming language for your Android app development project.

Let’s analyze and determine which one of them stands as a winner. Before getting started, let's have a look at both of them.

What is Kotlin?

Kotlin is a renowned programming language developed by JetBrains, open-source under Apache 2.0 license, making it completely free to use for any project. Based on Java Virtual Machine (JVM), Kotlin runs on all platforms that support JVM technology, including Windows, macOS, Linux, etc.

Being an OOP language like Java, Kotlin has many features of Java, such as a garbage collection mechanism to prevent memory leaks in your app. Furthermore, it offers some exciting features to develop Android apps much more straightforwardly than ever before.

Some of its most sought-after features are probably one of Kotlin's most significant advantages. It allows developers to write less code because its syntax is very similar to that of Java, and it can drastically reduce the time spent writing boilerplate code.

With proper naming conventions, Kotlin developers can easily keep their source clean with no risk of repeating themselves or skipping anything out when coding new elements since it will do what you mean rather than do what you say. As per Statista Survey 2020, Kotlin has a popularity of 8.32% among developers worldwide.

Moreover, not only does Kotlin compile quickly, but it compiles into readable bytecode too. Hence, there are no performance issues when running any application compiled with it in the production stage.

Pros of Using Kotlin Programming Language

  • Enhances Team Efficiency: Kotlin is a free, open-source language that's very similar to Java. Because of its extreme similarities to Java (the most popular programming language), Kotlin is extremely easy for developers who already know Java to learn.

    It eases interoperability between other languages and allows other coders to work with your code more efficiently, improving team efficiency. However, because Kotlin uses very few new keywords and syntax structures, if you don't already know how to program in Java, it will be slightly more difficult for you as you try to learn Kotlin.

    You'll also have no option but to use libraries written in Java until you know enough about Kotlin yourself.

  • Effortless Maintenance of Code: With Kotlin, there are no more code redundancies. It is an advantage for both maintainers and contributors to a project. There are no more bugs, which makes debugging easier. It also takes less time to release updates to new versions of libraries with Kotlin's self-contained packages. It means that developers can spend less time just waiting for release times rather than fixing things in apps that their users want to correct immediately.

  • Interoperable with Java: If you use a Java library in your Android app, you can reuse it with Kotlin. Kotlin is also interoperable with other JVM languages. For example, if you want to add some Scala code to your project, Kotlin will work fine with that too.

    Interoperability allows for a great deal of flexibility in choosing what type of language to use on any given project. Interoperability is often considered one of Java's best features—and now that interoperability is available to both Java and Android developers alike!

  • High Reliability: It gives you a more stable app than some other frameworks, as there's no risk of runtime errors. Kotlin code can integrate flawlessly with Java code, which means it can help improve an existing product instead of requiring a complete rewrite from scratch.

    Also, because Kotlin is compatible with most Android libraries, writing your app in Kotlin won't require switching away from any third-party libraries. It also adds to how reliable Kotlin is for developers looking to build a dedicated app.

Cons of Using Kotlin Programming Language

  • Despite being relatively easy to understand compared to other programming languages such as C++ or Java, Kotlin's syntax isn't appealing for non-programmers due to its reasonably complicated nature.

  • Building software using Kotlin requires a complete set of frameworks to make it work. Thus, having a stable internet connection is essential for people who want to develop software using Kotlin.

What is Java?

Sun Microsystems have developed the Java programming language in 1995, and it has since become the most preferred programming language in the world. It's suitable for creating web applications, mobile apps and desktop applications, and other types of software.

The pros and cons of Java provide an overview of the most important things to keep in mind when analyzing whether or not you should use this language on your next project.

Pros of using Java Programming Language

  • Easy to Learn: The Java syntax is relatively simple, as is its object-oriented coding model. It makes it relatively easy to pick up and get started with—no previous coding experience required. So if you're looking for a programming language that's relatively simple but still fairly powerful, Java may be an excellent place to start your coding journey.

  • Platform Independent: Yes, you read that right. You can develop your code once, and it will run on Windows, Mac OS X, Linux, Solaris, etc., on any machine with a JVM installed. It means you don't have to port your applications.

  • Strong Object-Oriented Programming Base: Like most modern programming languages, one of Java's great strengths is its ability to make OOP (object-oriented programming) a primary way to program.

  • Multiple Free Libraries: JavaScript libraries are often free to use for your websites or even custom projects. Free resources can be as robust as those that come with a fee; you have to know where to look.

  • Garbage Collection Saves Time: No more memory leaks! Garbage collection makes it a lot easier to program in a managed language. In unmanaged languages, you have to free-allocate memory explicitly.

    Otherwise, you can fall into all sorts of problems with memory leakage. With garbage collection, as long as your object is within an allocator that supports garbage collection, then they get cleaned up automatically when they're no longer in use.

  • You Need only One Codebase: For companies that want to write once and distribute anywhere, platform-independent languages like Java (programming language) offer a solution. Using these tools, you can produce applications for multiple platforms with little extra effort.

    You can target different operating systems or even web browsers using just one codebase. If your company wants to create apps for iOS devices and Android devices, writing in a platform-independent language can help you do it with just one set of code.

Cons of Using Java Programming Language

  • Performance is a big reason why developers avoid Java. The JVM (Java Virtual Machine) has to make many behind-the-scenes adjustments to run code, resulting in sluggish performance. At any given time, at least half of your CPU will get dedicated to just keeping JVM processes alive.

    When you're using other languages such as C++ or Python, there's much less work required from your computer's processor. As a result, these languages can return information more quickly than Java, leading to faster performance overall.

  • Since it's a statically typed language, you need to allocate memory for all your variables. Since static typing is more rigid than dynamic typing, you will get an error if you have missing or incompatible types in your program. That's why Java requires a high amount of memory.

Kotlin vs. Java:

Points of Comparison

Kotlin Programming Language

Java Programming Language

Who Wins?

Null Safety

It doesn’t allow the assignment of Null.

Allows the assignment of Null.

Kotlin wins


Compiles code to JVM.

Compiles programs to bytecode which the JVM runs.

You decide

Lines of Code

Lesser coding is required.

It requires more lines of code than Kotlin.

Kotlin wins

Lambda Expression (for writing short functions)

Available in source code of Kotlin.

Available in Java 8

Kotlin wins

Coroutines Support




Data Classes

Allows straightforward data classes creation

It needs improvement in making the approach more convenient.

Kotlin Leads

Checked Exceptions

Not Available


Java wins

Primitive Types

Automatically considers Primitive Types as objects.

Do not consider Primitive Types as objects.

Kotlin wins

Wildcard Types

Not Available


Java wins

Public Fields

Not Available


Java wins

When Should you Pick Kotlin?

Kotlin has been gaining popularity among Android app developers due to several reasons, such as its ease of use and flexibility, but it still falls behind Java in several ways. Top companies using Kotlin include Trello, Foursquare, etc.

Choose Kotlin when you're developing enterprise-grade apps or want to work with a large community of developers on an open-source platform.

In that case, Kotlin may not be your first choice because it doesn't have all the features that other languages do.

When Should you Pick Java?

The significant benefit of choosing Java as your development language is that it's easy to find and hire Java developers with experience, which means you won't need to invest as much time and money training new staff.

Many companies and organizations still use Java as their development language, including Amazon, Uber, eBay, Google, Netflix, etc.

If your needs are elementary, such as a website or smartphone app that doesn't require a ton of processing power, then choosing Java may be the best choice for you.

Who’s the Ultimate Winner for Business Enterprises?

Well, the answer is obvious, Kotlin wins, and the reason is as follows:

  • It leads to fewer system failures and app crashes.
  • It provides enhanced support for functional programming.
  • Lesser lines of code save time & money for the investors.
  • It facilitates rapid bug detection.
  • It comes with in-built null safety.

Wrapping Up

Closing out a Kotlin vs. Java discussion, it's essential to consider that Kotlin and Java are for different purposes, with additional features and functionalities. The idea is to check for the project requirements with the available features over the two Languages.

When deciding on a programming language, it's all about knowing what you want from your app or business process, finding a functional tool for reaching those goals, and choosing your tools based on your company's needs.

In most cases, businesses might decide to use both languages (Android Studio supports them), keeping in mind that support for Kotlin could change depending on how widespread its adoption becomes within Android development circles.


Question: What other Programming Languages can I use for developing Android Apps?

Answer: There are multiple options for you, however apart from Java and Kotlin, the following are the other reputed options:

Python: Python is prevalent among developers who are looking for a little more flexibility. Because it allows you to work quickly and easily, Python is considered one of the best programming languages for developing games on Android. That's because it's very versatile and has excellent syntax support (which means that errors are far less likely).

Many developers also like its automatic memory management, which automatically frees up space when you no longer need it. However, the drawback is that there aren't as many libraries available for Python as for Java or some other languages, which means programmers have less support from third parties in open-source code libraries.

C++: It is listed among the most popular programming languages in use today. One of its strengths is that it's multi-platform compatible, meaning you can write an app once and run it on any device, be it a PC or mobile.

But because C++ is also suitable for software development, many computer language enthusiasts shy away from Android due to their inability to write native apps using Java or other languages. However, if you are determined to write your application using C++, several tools are available that will get you started quickly.

C#: It is renowned for its cross-platform capabilities, and the programming language has been increasing in popularity for years. It's a good choice if you're looking to target both iOS and Android at once.

Though it won't have as much third-party support as Swift or Java, it will still produce a high-quality product with a solid development community. When writing in C#, keep an eye out for Xamarin's tools; they make it easier than ever to create native mobile apps using .NET languages like C#.

Question: What is Android SDK?

The Android Software Development Kit (SDK) comprises everything necessary for developing apps for Android-powered devices. The SDK provides all of the relevant libraries, APIs, and tools to get started developing.

It includes things like Google Play Services, which allows users to log in via their Google accounts; AdMob, an advertising library; Google Analytics, which helps you track how people are using your app; and more.

You also get sample code and other tutorials that demonstrate how all of these things work together. It's important to note that it's not necessary to use all of these components—you can write your app without them if needed—but they're there if you need them.

Question: What's the Cost & Time for Developing a Simple Android app?

Answer: It depends on how advanced you want your app to be, but it generally takes around four weeks to design and code a simple app. It can cost anywhere from $5,000 to $20,000. More complex apps take approximately eight weeks to develop, at the cost of between $15,000 and $30,000.

The more complicated an app is, particularly if it has video or other multimedia elements, the higher its price tag. You should also remember that coding is just one aspect of an app's development—there are other crucial components such as art design and marketing.

Apps are marketed in much the same way as products are, so many different factors can increase or decrease development costs.

Question: I am still confused about which one I should choose for my project?

Answer: Feel free to connect with us as we offer complimentary consultation on projects. Our dedicated team of coders will help you choose the best programming language for your app or software development project.

Question: What are the leading Android apps worldwide?

Answer: As per Statista, following are the leading Android apps worldwide,

Source: Statista