Java Vs. Kotlin: Which One Will Be the Best in 2019?

Kotlin is this flashy new kid, the raging bull, armed with loads of features and the backing of the biggest tech conglomerate of the earth. Java is the oldest. Hence it owns the tag of being the first at the scene, and naturally, it dominates the market. Java is everywhere! But Kotlin is fast catching-up, though it still has a long way to go. 

In all honesty, it boils down to the user’s preferences. It’s essential to understand the distinction between the two before making the switch.

If there is one thing that distinguishes the two at face value, then it’s the explosive growth in Kotlin’s popularity. Ever since it received recognition from Google back in 2017 as the second official language for Android app development, observes have witnessed a monumental rise in Kotlins’ demand for both the app-enterprise and app-developer circles. And Kotlin has in a short period proved its worth as a pragmatic, modern, and intuitive programming language. IT could be safe to say, that whosoever shall give Kotlin a try is bound to fall in love with it. 



Kotlin was developed by Russian company JetBrains back in 2011. The company is also famous for pioneering the IntelliJ IDEA, PyCharm, and many other top IDEs. The source of inspiration for the name of Kotlin came from Kotlin Island in St. Petersburg, Russia. Kotlin was created with a direct purpose, that of being better than Java in every possible way. Kotlin addresses several of Java’s weaknesses as well. And since JetBrains didn’t put the effort to write Kotlins entire new IDE from scratch, hence the 100% interoperability with Java. 


Java vs Kotlin: Market Share

Java, without doubt, commands a tremendous influence on the world of mobile app development, and the below-presented chart from Tiobe Index backs this up. As of June last year, Java continued to dominate the market-share vis-a-vis 2017 as the most popular language. Kotlin, though still a young language, has made it to the top 50 of the rankings, setting down at number 49. 


Growth in Kotlins popularity, region-wise post-Google support announcement


However, ever since the Google I/O 2017 conference that had featured promotions and support for Kotlin by Google. This marked the entry of Kotlin into the league of programming languages like Java and C++. Google’s backing has caused a spectacular growth in its popularity in Kotlins popularity. 


Java vs Kotlin: Verbosity

One of the most significant shortcomings of Java is its verbosity. Also a big source of frustration for the developer! In contrast, Kotlin, in essence, was designed to correct this. Meaning, lesser the number of boilerplate code the developer has to write, and so forth. 


Verbosity of Java v/s Kotlin. Check-out the reduced number of lines for the same result. 


According to JetBrains, the number of lines of code one has to write in Kotlin are approx 40% less as compared to Java. Operational tests for the same present a slightly diminished reduction in the rate of code lines, that of 30%. Post the conversion of “App Lock” app from Java into Kotlin, the number of code lines came down to 8,564 for Kotlin, as against 12,371 from lines of Java.

Kotlin also fares better than Java when it comes to the number and the kind of features it supports –

  • Extensions – Extend class functionality;
  • Null-safety – Prevent null references from occurring. Reduces the risk of faults in apps;
  • Coroutines – Reduce the occurrence of thread blocking. Minimize the risk of errors, and more.

In the longer-run, a more robust and safe code can be written with fewer efforts. The time needed for the amount of the output generation and bugs fixing cuts down.

In the longer-run, a more robust and safe code can be written with fewer efforts — the time needed for the amount of the output generation and bugs fixing cuts down.


Java vs Kotlin: Performance & Compile Time

As per JetBrains, similarities in the bytecode structure enable the applications built on Kotlin to run as fast as an equivalent to an app built on Java. Kotlin’s support for inline functions allows code using lambdas to run even quicker than the same code written in Java.

In addition to this, tests also show that for clean builds Java compiles 10-15 % faster as compared to Kotlin. Kotlin performs identical to Java or even slightly better when it comes to incremental compilation. Reductions in compile-time imply more productivity for the developer.


Java vs Kotlin: Android Studio 3.0 Support

Java implementation in Android ecosystem seems to lag behind the demands of the developers’ community. Though the latest version of Java is SE 10, Android Studio 3.0 and later supports Java 7 and only some of Java 8 features. Thus, developers that are denied the opportunity to embrace the full potential of the latest versions are starting to shift more towards Kotlin. Bearing in mind that Android Studio is based on the JetBrains’ IntelliJ IDEA, it is easy to predict its excellent support for Kotlin.

The numerous limitations within Java are known to impede with Android API design. And Kotlin’s strengths outweigh the language’s setbacks. It is inherently clean, far less tedious and lightweight, especially in terms of writing callbacks and data classes. A significant advantage of Kotlin is the solutions to API design deficiencies that are inherent to Java. 


Confused? Interchangeability is the name of the game

As stated earlier, there are some features which are better in Kotlin. While Java fares better in some of the app-development departments. 

For those eager to work with both, i.e., maximize their developer efforts with the benefits from each have much to rejoice as interchangeability is the name of the game.

Both Java and Kotlin are fully interoperable, irrespective of all the dissimilarities between the two. Both compile to bytecode, which makes it possible to call Java code from Kotlin and vice-versa. This flexibility has two advantages. First, it facilitates getting started with Kotlin by incrementally introducing the Kotlin code in a Java project. Second, both languages can be used simultaneously in any Android application development project.


Is this the end of Java? Mixed opinions from the developer community – 

A programming language of eminence, and with a presence on every continent – Java has immense open-source tools and libraries. No programming language is perfect. Java is subject to numerous complications that can make a developer’s job tedious. But one thing is sure here, that Kotlin would unveil solutions to common programming headaches that would eventually improve the entire developer ecosystem as a whole.

The past two years have made Kotlin more stable and a more harmonious development option for Android Studio. It’s safe, concise, interoperable and tool-friendly. And the rise in Kotlins utility has got some developers to believe that it’ll oust Java in the coming years. And then many experts say that both Kotlin and Java are going to coexist in the world of android development, without one outweighing the other. Only time can tell!

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Written by DreamzTech
DreamzTech Solutions Inc is a US based International software firm. The US division of the global network Dreamztech, is headquartered in Tempe, Arizona. Specializing in Web and Mobile based platforms suited for any size of business. From building a complete website or mobile app, to an Enterprise Corporate Solution Dreamztech Solutions Inc. can handle it. Our priority is to establish a long term relationship with our clients and deliver their VISION. Call us today to discuss your upcoming project @ (800) 893-2964.