{"id":23542,"date":"2026-02-15T00:34:42","date_gmt":"2026-02-14T19:04:42","guid":{"rendered":"https:\/\/www.techgropse.com\/blog\/?p=23542"},"modified":"2026-04-21T13:41:05","modified_gmt":"2026-04-21T08:11:05","slug":"java-to-kotlin-migration-guide","status":"publish","type":"post","link":"https:\/\/www.techgropse.com\/blog\/java-to-kotlin-migration-guide\/","title":{"rendered":"From Java to Kotlin (Evolution of Mobile App Development): A Complete Guide"},"content":{"rendered":"<p><span style=\"font-weight: 400;\">To meet the modern requirements, mobile applications were discovered. This discovery quickly became a revolution and turned into a necessity for humans. Java is a part of this evolution and has been with us for decades for mobile app development.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Java is useful for developing Android applications. However, it has some gaps that are filled by its successor, Kotlin. These advantages have contributed to Kotlin\u2019s rapid adoption, with Android developers increasingly favoring it over Java. As of <\/span><a href=\"https:\/\/www.androidmetro.com\/2024\/01\/android-kotlin-vs-java-market-share.html\" target=\"_blank\" rel=\"noopener\"><b>2024-25<\/b><\/a><span style=\"font-weight: 400;\">, Android developers choose Kotlin (with 70 to 75% market share) over Java (25 to 30% market share).<\/span><\/p>\n<p><span style=\"font-weight: 400;\">In this guide, you will explore the differences between Java and Kotlin, why migration is necessary, and how TechGropse\u2019s Java to Kotlin migration services can help.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Let\u2019s get started!<\/span><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_76 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"#\" data-href=\"https:\/\/www.techgropse.com\/blog\/java-to-kotlin-migration-guide\/#What_is_Java\" >What is Java?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"#\" data-href=\"https:\/\/www.techgropse.com\/blog\/java-to-kotlin-migration-guide\/#What_is_Kotlin\" >What is Kotlin?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"#\" data-href=\"https:\/\/www.techgropse.com\/blog\/java-to-kotlin-migration-guide\/#Java_vs_Kotlin_A_Comparison_Table\" >Java vs Kotlin: A Comparison Table<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"#\" data-href=\"https:\/\/www.techgropse.com\/blog\/java-to-kotlin-migration-guide\/#Differences_Between_Kotlin_and_Java_Explained\" >Differences Between Kotlin and Java, Explained<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"#\" data-href=\"https:\/\/www.techgropse.com\/blog\/java-to-kotlin-migration-guide\/#Why_Modernize_Your_App_From_Java_to_Kotlin_in_2026\" >Why Modernize Your App From Java to Kotlin in 2026?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"#\" data-href=\"https:\/\/www.techgropse.com\/blog\/java-to-kotlin-migration-guide\/#How_to_Migrate_From_Java_to_Kotlin\" >How to Migrate From Java to Kotlin?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"#\" data-href=\"https:\/\/www.techgropse.com\/blog\/java-to-kotlin-migration-guide\/#Conclusion\" >Conclusion<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"What_is_Java\"><\/span><b>What is Java?<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Launched in May 1995, Java is a general-purpose and object-oriented programming language. Earlier, it had the lion\u2019s share as it was used by multiple Android developers. However, it still stands as the third most used programming language, with <\/span><a href=\"https:\/\/lemon.io\/blog\/most-popular-programming-languages\/\" target=\"_blank\" rel=\"noopener\"><b>around 30% of developers<\/b><\/a><span style=\"font-weight: 400;\"> using Java regularly. Since its inception, Java has expanded its functionality and usability through its various versions.<\/span><\/p>\n<div class=\"custom-spacer\" contenteditable=\"false\"><\/div>\n<p><b>Also Read:<\/b> <a href=\"https:\/\/www.techgropse.com\/java\"><b>Java App Development<\/b><\/a><\/p>\n<p>&nbsp;<\/p>\n<table>\n<tbody>\n<tr>\n<td><b>Java Version<\/b><\/td>\n<td><b>Release Year<\/b><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">JDK 1.0<\/span><\/td>\n<td><span style=\"font-weight: 400;\">1996<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">JDK 1.1<\/span><\/td>\n<td><span style=\"font-weight: 400;\">1997<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">J2SE 1.2<\/span><\/td>\n<td><span style=\"font-weight: 400;\">1998<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">J2SE 1.3<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2000<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">J2SE 1.4<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2002<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">J2SE 5.0 (1.5)<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2004<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 6<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2006<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 7<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2011<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 8<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2014<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 9<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2017<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 10<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2018<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 11<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2018<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 12<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2019<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 13<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2019<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 14<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2020<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 15<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2020<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 16<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2021<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 17<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2021<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 18<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2022<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 19<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2022<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 20<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2023<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 21<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2023<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Java SE 24<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2025<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3><\/h3>\n<h3><b>Benefits<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Irrespective of longer code lines, Java is quite a simple and easy-to-understand programming language. The syntax of this language is quite straightforward to learn and understand.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Being an object-oriented programming language, Java facilitate reusabilty of the code. With OOPs, we can easily reuse the objects in other programs.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Other programming languages, like C\/C++, use pointers to enable access to memory locations. This is a security risk that is addressed by Java through encapsulation, inheritance, and abstraction.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The Java programming language is highly portable as it is platform-independent and runs on any hardware. It makes Java compatible with multiple devices.<\/span><\/li>\n<\/ul>\n<h3><b>Limitations<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Java is slower and consumes more memory compared to the alternatives available in the market.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Java\u2019s frameworks, like Swing, SWT, JavaFX, JSF, etc., are not well developed to generate complex UIs.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">No backup facility for the stored user data as it focus preliminary on data storage and not on backup.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Java is quite verbose and comes with complex syntax. It is hard for developers to remember those complex syntaxes.<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_is_Kotlin\"><\/span><b>What is Kotlin?<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/en.wikipedia.org\/wiki\/Kotlin\" target=\"_blank\" rel=\"noopener\"><span style=\"font-weight: 400;\"><strong>Released in<\/strong> <\/span><b>2016<\/b><\/a><span style=\"font-weight: 400;\">, Kotlin is a modern programming language. It has gained popularity for its compatibility with Java. It is primarily used to build modern mobile apps, web apps, server-side apps, etc. It offers a concise and expressive syntax that reduces boilerplate code, making development faster and more efficient.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-23550 size-full\" src=\"https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/GOOGLE.png\" alt=\"GOOGLE\" width=\"1192\" height=\"571\" srcset=\"https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/GOOGLE.png 1192w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/GOOGLE-300x144.png 300w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/GOOGLE-1024x491.png 1024w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/GOOGLE-768x368.png 768w\" sizes=\"auto, (max-width: 1192px) 100vw, 1192px\" \/><\/p>\n<p>&nbsp;<\/p>\n<h3><b>Benefits<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Kotlin doesn\u2019t leave any scope to make errors, considering its lightweight codebase. Its compiler can detect errors, making it a safe Java alternative.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">It has an intuitive syntax and makes it possible to do more work as it takes less time and fewer lines of code to write and deploy code.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Kotlin makes it possible to use it along with Java at the same time to write code for the same product.<\/span><\/li>\n<\/ul>\n<h3><b>Limitations<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The Kotlin programming language has a slower compilation time compared to Java, especially while working on large projects.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Not easy to learn for beginners who find its advanced features a little complex.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Kotlin apps may have a slightly larger APK size due to additional runtime libraries.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Although fully interoperable with Java, certain features (like null-safety and checked exceptions) can cause minor compatibility challenges.<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Java_vs_Kotlin_A_Comparison_Table\"><\/span><b>Java vs Kotlin: A Comparison Table<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>&nbsp;<\/p>\n\n<table id=\"tablepress-339\" class=\"tablepress tablepress-id-339\">\n<thead>\n<tr class=\"row-1 odd\">\n\t<th class=\"column-1\">Feature<\/th><th class=\"column-2\">Java<\/th><th class=\"column-3\">Kotlin<\/th>\n<\/tr>\n<\/thead>\n<tbody class=\"row-hover\">\n<tr class=\"row-2 even\">\n\t<td class=\"column-1\">Year Introduced<\/td><td class=\"column-2\">1996<\/td><td class=\"column-3\">2011<\/td>\n<\/tr>\n<tr class=\"row-3 odd\">\n\t<td class=\"column-1\">Official Android Support<\/td><td class=\"column-2\">Primary language before 2019<\/td><td class=\"column-3\">Preferred Android language since 2019<\/td>\n<\/tr>\n<tr class=\"row-4 even\">\n\t<td class=\"column-1\">Syntax<\/td><td class=\"column-2\">Verbose and boilerplate-heavy<\/td><td class=\"column-3\">Concise and expressive<\/td>\n<\/tr>\n<tr class=\"row-5 odd\">\n\t<td class=\"column-1\">Null Safety<\/td><td class=\"column-2\">Prone to NullPointerException<\/td><td class=\"column-3\">Built-in null safety<\/td>\n<\/tr>\n<tr class=\"row-6 even\">\n\t<td class=\"column-1\">Code Length<\/td><td class=\"column-2\">Requires more lines of code<\/td><td class=\"column-3\">Reduces boilerplate by ~30-40%<\/td>\n<\/tr>\n<tr class=\"row-7 odd\">\n\t<td class=\"column-1\">Learning Curve<\/td><td class=\"column-2\">Easier for beginners<\/td><td class=\"column-3\">Slightly steeper for beginners<\/td>\n<\/tr>\n<tr class=\"row-8 even\">\n\t<td class=\"column-1\">Performance<\/td><td class=\"column-2\">Stable and reliable<\/td><td class=\"column-3\">Comparable performance (runs on JVM)<\/td>\n<\/tr>\n<tr class=\"row-9 odd\">\n\t<td class=\"column-1\">Coroutines \/ Async<\/td><td class=\"column-2\">Requires complex threading<\/td><td class=\"column-3\">Built-in coroutines for async programming<\/td>\n<\/tr>\n<tr class=\"row-10 even\">\n\t<td class=\"column-1\">Extension Functions<\/td><td class=\"column-2\">Not supported<\/td><td class=\"column-3\">Supported<\/td>\n<\/tr>\n<tr class=\"row-11 odd\">\n\t<td class=\"column-1\">Interoperability<\/td><td class=\"column-2\">Native language<\/td><td class=\"column-3\">100% interoperable with Java<\/td>\n<\/tr>\n<tr class=\"row-12 even\">\n\t<td class=\"column-1\">Community &amp; Ecosystem<\/td><td class=\"column-2\">Mature, large ecosystem<\/td><td class=\"column-3\">Rapidly growing ecosystem<\/td>\n<\/tr>\n<tr class=\"row-13 odd\">\n\t<td class=\"column-1\">Use in Legacy Systems<\/td><td class=\"column-2\">Widely used<\/td><td class=\"column-3\">Less common in legacy systems<\/td>\n<\/tr>\n<tr class=\"row-14 even\">\n\t<td class=\"column-1\">Enterprise Adoption<\/td><td class=\"column-2\">Strong enterprise presence<\/td><td class=\"column-3\">Growing enterprise adoption<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- #tablepress-339 from cache -->\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.techgropse.com\/contact\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-23546 size-full\" src=\"https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Willing-to-Migrate-Your-Android-Mobile-App-From-Java-to-Kotlin_.png\" alt=\"Willing to Migrate Your Android Mobile App From Java to Kotlin\" width=\"1267\" height=\"374\" srcset=\"https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Willing-to-Migrate-Your-Android-Mobile-App-From-Java-to-Kotlin_.png 1267w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Willing-to-Migrate-Your-Android-Mobile-App-From-Java-to-Kotlin_-300x89.png 300w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Willing-to-Migrate-Your-Android-Mobile-App-From-Java-to-Kotlin_-1024x302.png 1024w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Willing-to-Migrate-Your-Android-Mobile-App-From-Java-to-Kotlin_-768x227.png 768w\" sizes=\"auto, (max-width: 1267px) 100vw, 1267px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Differences_Between_Kotlin_and_Java_Explained\"><\/span><b>Differences Between Kotlin and Java, Explained<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><b>Code Less With Kotlin<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Coding with Kotlin is generally easier compared to Java.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">You need to write 30 to 40% less code while writing in Kotlin. It simply means faster development and less scope for bugs.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Let\u2019s understand the difference in code length with an example of Java (image 1.1) and Kotlin (image 1.2).<\/span><\/p>\n<p>&nbsp;<\/p>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">package com.example.helloworld;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">import android.os.Bundle;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">import android.widget.TextView;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">import androidx.appcompat.app.AppCompatActivity;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">public class MainActivity extends AppCompatActivity {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0@Override<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0protected void onCreate(Bundle savedInstanceState) {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0super.onCreate(savedInstanceState);<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TextView textView = new TextView(this);<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0textView.setText(&#8220;Hello, World!&#8221;);<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0setContentView(textView);<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0}<\/span><\/p>\n<p><span style=\"font-weight: 400;\">}<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-weight: 400;\">Image 1.1<\/span><\/p>\n<p>&nbsp;<\/p>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">package com.example.helloworld<\/span><\/p>\n<p><span style=\"font-weight: 400;\">import android.os.Bundle<\/span><\/p>\n<p><span style=\"font-weight: 400;\">import android.widget.TextView<\/span><\/p>\n<p><span style=\"font-weight: 400;\">import androidx.appcompat.app.AppCompatActivity<\/span><\/p>\n<p><span style=\"font-weight: 400;\">class MainActivity : AppCompatActivity() {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0override fun onCreate(savedInstanceState: Bundle?) {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0super.onCreate(savedInstanceState)<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0setContentView(TextView(this).apply {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0text = &#8220;Hello, World!&#8221;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0})<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0}<\/span><\/p>\n<p><span style=\"font-weight: 400;\">}<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-weight: 400;\">Image 1.2<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">Here, it is clear that Java requires multiple lines for classes, imports, and object creation. On the other hand, Kotlin is 30 to 40% shorter and simpler. And the Kotlin version is much more readable than Java.<\/span><\/p>\n<h3><b>Preventing Null Errors<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Kotlin has some performance benefits over Java, as it has some features that Java doesn\u2019t like <\/span><b>Null Safety<\/b><span style=\"font-weight: 400;\">. It can enhance the overall performance of an application.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Null safety is a key distinction between Kotlin and Java. In Java, variables can hold null values by default, which often leads to NullPointerExceptions at runtime. Kotlin, however, forces developers to explicitly declare whether a variable can be null, significantly reducing the risk of such runtime errors.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Let\u2019s understand the difference in code length with an example of Java (image 2.1) and Kotlin (image 2.2).<\/span><\/p>\n<p>&nbsp;<\/p>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">public class Main {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0public static void main(String[] args) {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0String name = null; \/\/ null is allowed<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0System.out.println(name.length()); \/\/ Throws NullPointerException at runtime!<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0}<\/span><\/p>\n<p><span style=\"font-weight: 400;\">}<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-weight: 400;\">Image 2.1<\/span><\/p>\n<p>&nbsp;<\/p>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">fun main() {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0var name: String? = null \/\/ Must explicitly allow null with &#8216;?&#8217;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0println(name?.length)\u00a0 \u00a0 \/\/ Safe call; prints &#8216;null&#8217; instead of crashing<\/span><\/p>\n<p><span style=\"font-weight: 400;\">}<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-weight: 400;\">Image 2.2<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">As you can see, with Java, you can get a runtime error (NullPointerException). Whereas, in Kotlin, a variable can\u2019t be null by default.<\/span><\/p>\n<h3><b>Functional Programming<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">One of the big differences between Kotlin and Java is functional programming. Java introduced <\/span><b>Java8<\/b><span style=\"font-weight: 400;\"> for it, after which it supported functional programming. On the other hand, Kotlin supported it from day 1, making it an ideal choice for developing an application.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><b>Functional Programming Example (after Java8)<\/b><\/p>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">import java.util.Arrays;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">import java.util.List;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">public class Main {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0public static void main(String[] args) {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0List&lt;String&gt; names = Arrays.asList(&#8220;Alice&#8221;, &#8220;Bob&#8221;, &#8220;Charlie&#8221;);<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/ Using streams (Java 8+) to filter and print names starting with &#8216;A&#8217;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0names.stream()<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0.filter(name -&gt; name.startsWith(&#8220;A&#8221;))<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0.forEach(System.out::println);<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0}<\/span><\/p>\n<p><span style=\"font-weight: 400;\">}<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p><b>Functional Programming Example (Kotlin)<\/b><\/p>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">fun main() {<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0val names = listOf(&#8220;Alice&#8221;, &#8220;Bob&#8221;, &#8220;Charlie&#8221;)<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\/\/ Filter and print names starting with &#8216;A&#8217; using functional style<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0names.filter { it.startsWith(&#8220;A&#8221;) }<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0.forEach { println(it) }<\/span><\/p>\n<p><span style=\"font-weight: 400;\">}<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><\/h2>\n<h2><span class=\"ez-toc-section\" id=\"Why_Modernize_Your_App_From_Java_to_Kotlin_in_2026\"><\/span><b>Why Modernize Your App From Java to Kotlin in 2026?<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Modernizing an Android app from Java to Kotlin in 2026 is a strategic move as it provides businesses with efficiency and long-term stability. Kotlin has a concise syntax, null-safety features, and native support for functional programming to accelerate development and reduce cost to improve ROI. However, CTOs still want to know the benefits of migrating from Java to Kotlin for business<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Kotlin codes are easier to understand as they are cleaner, which makes it easier to update later.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Kotlin is simple and makes code easier to maintain. Its code length is about 20 to 30% less compared to Java.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Kotlin supports faster development by boosting the app developer productivity. More than 60% of developers prefer Kotlin over Java.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Kotlin prevents null-pointer exceptions, which is a bug that results in app crashes.<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-23545 size-full\" src=\"https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Why-Modernize-Android-Mobile-Apps_-1.png\" alt=\"Why Modernize Android Mobile Apps\" width=\"1920\" height=\"1080\" srcset=\"https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Why-Modernize-Android-Mobile-Apps_-1.png 1920w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Why-Modernize-Android-Mobile-Apps_-1-300x169.png 300w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Why-Modernize-Android-Mobile-Apps_-1-1024x576.png 1024w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Why-Modernize-Android-Mobile-Apps_-1-768x432.png 768w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/Why-Modernize-Android-Mobile-Apps_-1-1536x864.png 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><\/p>\n<p>&nbsp;<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_to_Migrate_From_Java_to_Kotlin\"><\/span><b>How to Migrate From Java to Kotlin?<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Migrating from Java to Kotlin is quite a straightforward process considering its excellent interoperability and built-in IDE tooling. It facilitates file-by-file conversion to integrate Kotlin into your existing Java code without disruption.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Sounds too much?<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Don\u2019t worry, TechGropse, a leading Android app modernization company, provides Java to Kotlin migration services. These services are available at an affordable price so that businesses of all sizes can avail it.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Moreover, TechGropse enables businesses to hire Kotlin app developers for the modernization of legacy Android apps.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-23544 size-full\" src=\"https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/How-TechGropse-Can-Help-in-Migration_-1.png\" alt=\"How TechGropse Can Help in Migration_ (1)\" width=\"1920\" height=\"1080\" srcset=\"https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/How-TechGropse-Can-Help-in-Migration_-1.png 1920w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/How-TechGropse-Can-Help-in-Migration_-1-300x169.png 300w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/How-TechGropse-Can-Help-in-Migration_-1-1024x576.png 1024w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/How-TechGropse-Can-Help-in-Migration_-1-768x432.png 768w, https:\/\/www.techgropse.com\/blog\/wp-content\/uploads\/2026\/02\/How-TechGropse-Can-Help-in-Migration_-1-1536x864.png 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><\/p>\n<p>&nbsp;<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span><b>Conclusion<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Both Kotlin and Java are incredible programming languages that are somewhat similar to each other (with a few differences). While Java has been here for a longer period of time, Kotlin has replaced it as its modern successor. It is an improved version of it that has addressed the gaps caused by Java.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Business owners and CTOs with apps in Java want to modernize their Android apps with Java; they can use TechGropse\u2019s Java to Kotlin migration services for it. TechGropse has the capability of modernizing the architecture of the existing app and making it viable to stay competitive in this digital world.<\/span><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>To meet the modern requirements, mobile applications were discovered. This discovery quickly became a revolution and turned into a necessity for humans. Java is a part of this evolution and has been with us for decades for mobile app development. Java is useful for developing Android applications. However, it has some gaps that are filled [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":23543,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[191],"tags":[],"table_tags":[3540],"country":[],"country_map":[],"class_list":["post-23542","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technology","table_tags-java-vs-kotlin-a-comparison-table"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/posts\/23542","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/comments?post=23542"}],"version-history":[{"count":4,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/posts\/23542\/revisions"}],"predecessor-version":[{"id":24730,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/posts\/23542\/revisions\/24730"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/media\/23543"}],"wp:attachment":[{"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/media?parent=23542"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/categories?post=23542"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/tags?post=23542"},{"taxonomy":"table_tags","embeddable":true,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/table_tags?post=23542"},{"taxonomy":"country","embeddable":true,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/country?post=23542"},{"taxonomy":"country_map","embeddable":true,"href":"https:\/\/www.techgropse.com\/blog\/wp-json\/wp\/v2\/country_map?post=23542"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}