Kotlin vs Java: What is Good For Mobile App Development?

The Android environment maintains its rapid pace of evolution, presenting developers with essential technology stack decisions to face. Using Kotlin or Java to create modern, stable applications is a foremost choice.

Java has long been the de facto Android programming language, and it has always been stable and compatible on numerous platforms. This opposes Kotlin, a new programming language that addresses some of Java’s deficits and offers new features.

Both languages now exist as practical languages in their own right, with each language having pros and cons for a particular philosophy of the programming developer. The decision to use Kotlin or Java is not a simple search to determine the “best” programming language but rather is about finding the right solution for your project. 

In this blog post, you will learn a complete comparison of Kotlin vs. Java for mobile development, and you can choose the best one.

Kotlin or Java: What’s the Difference?

Java

Java is an established, object-oriented programming language noted for its stability, platform independence through the JVM, and firm performance. It was the first language to develop Android apps and remains the most used language for creating stable mobile apps.

Java also has practical use cases in enterprise software, web applications using framework tools like Spring, and software that analyzes large amounts of data using tools like Hadoop. In addition, Java’s strict type-checking and exception-handling capabilities make Java a top choice when programming large-maintainable software projects where stability is required.

Pros of Java

• Mature ecosystem – Extensive libraries and frameworks.
• High performance – Optimized for CPU-intensive tasks.
• Platform independence – Runs on any device with JVM.
• Strong community – Over 10M+ developers worldwide.

Cons of Java

• Verbose syntax – Requires more boilerplate code.
• Null Pointer Exceptions – No built-in null safety.
• Slower development – Compared to Kotlin’s concise syntax.

Kotlin

Kotlin has emerged as the new, easy-to-use replacement for Java for Android development and has been Google’s officially supported language of choice since 2019. JetBrains created a programming language to react to Java’s verbose syntax without sacrificing full interoperability with Java.

Although Kotlin’s design is pragmatic, the language offers practical advantages, like less boilerplate code for a more expressive syntax than Java. The language incorporates built-in null safety features that eliminate the notorious Null Pointer Exception crashes plaguing Java applications. 

For modern app requirements, Kotlin provides coroutines for simplified asynchronous programming and Kotlin Multiplatform (KMM) for sharing business logic between Android and iOS platforms. 

Pros of Kotlin

• Modern & expressive – Faster development.
• 100% Java interoperability – Seamless integration.
• Safer code – Built-in null checks.
• Growing adoption – 70% of new Android projects use Kotlin (2025 stats).

Cons of Kotlin

• Smaller legacy codebase – Fewer old projects compared to Java.
• Steeper learning curve – Functional programming concepts.

Java vs Kotlin: A Detailed Comparison 

The critical comparisons between the two mobile app development languages are as follows:

Ease-Of-Use & Learning Curve

In 2025, Kotlin has solidified its position as the more developer-friendly language for Android development. Its concise syntax reduces typical coding tasks compared to Java, allowing developers to focus on logic rather than boilerplate. 

Google’s continued investment in Kotlin tooling has resulted in Android Studio 2025 featuring AI-assisted Kotlin code completion that predicts common patterns.

Key advantages that make Kotlin easier to adopt:

• Intuitive syntax with type inference and lambda expressions
• Null safety built into the type system prevents common crashes
• Extension functions let developers add features to existing classes
• Coroutines simplify asynchronous programming

While Java remains essential to learn due to its prevalence in legacy systems, most new Android developers in 2025 start with Kotlin first before learning Java interoperability.

Performance

Recent benchmarks in 2025 show a fascinating Kotlin vs Java performance landscape:

Kotlin’s performance benefits come from several architectural improvements:

• Inline functions eliminate function call overhead
• Immutable collections enable safer concurrency
• Coroutines reduce thread management costs

However, Java maintains an edge in raw computational performance for:

• Heavy mathematical operations
• Low-latency financial systems
• Legacy applications optimized for JVM

Popularity & Industry Adoption

Although Kotlin is a more recent language, it has quickly become one of the most popular options for creating Android apps. In addition, Google supports Kotlin, which guarantees it will gain more support and advance over time. However, if we discuss the present, Java would be more popular than Kotlin.

The 2025 developer ecosystem shows Kotlin leading in new Android projects while Java maintains enterprise strongholds:

Kotlin Growth Drivers:

• Google’s mandate for all first-party Android apps to use Kotlin
• Most of Play Store’s apps now use Kotlin
• JetBrains’ KMM platform reaching 1.0 stability

Java’s Continued Relevance:

• Required skill for maintaining legacy Android apps
• Preferred choice for banking and healthcare systems

Development Across Platforms

Java is constrained by its usage of bytecode, which can only be compiled for one platform at a time. The cross-platform landscape has dramatically shifted by 2025. Kotlin Multiplatform (KMM) now allows sharing code between Android and iOS, with companies like Netflix and Airbnb reporting:

• Faster feature development
• Reduction in platform-specific bugs
• Unified team collaboration

Java remains limited in this area, though new projects like Project Panama aim to improve native interoperability. For teams developing for:

• Android + iOS → KMM is the clear choice
• Web + Mobile → Consider Kotlin/JS
• Enterprise Backends → Java still dominates

Library Support & Ecosystem

The library ecosystem has matured significantly for both languages:

Kotlin’s Strengths

• Jetpack Compose (adopted by most of the new Android UI code)
• Ktor framework for networked applications
• Kotlin Serialization for JSON processing

Java’s Advantages

• Spring Boot for enterprise applications
• Better support for legacy Android libraries
• More mature big data tools (Hadoop, Spark)

Notably, many popular Java libraries now offer Kotlin-first versions, reducing the previous gap in available tooling.

Scalability Considerations

Although Kotlin and Java are excellent options for application development, both languages face possible scalability issues compared to the lower-level programming language C. Performance issues on older Android devices could still occur due to excessive memory execution of the applications. 

However, Kotlin’s up-to-date design structure improves performance and scalability by utilizing inline functions and a more effective bytecode generation, which can reduce resource utilization.

For projects requiring optimal performance across diverse devices, Kotlin’s leaner architecture often proves more scalable than traditional Java implementations, especially when combined with modern Android development practices.

Community Assistance

The developer communities for Kotlin and Java present contrasting advantages. Java benefits from decades of accumulated knowledge, with extensive documentation and proven solutions for virtually every development scenario. 

While newer, Kotlin has rapidly grown its community since Google’s endorsement, offering more modern learning resources tailored to current development needs. Kotlin is becoming the preferred language for many companies because its community is engaged and generates wisdom with best practices quickly, while Java still brings value in maintaining existing systems. 

Developers new to the field find Kotlin easier to learn due to its concise syntax and the excellent documentation officially provided by JetBrains and Google.

Kotlin vs Java: Which One is Better for Android Development?

Kotlin and Java are both great options for modern Android development. They offer unique advantages for particular development scenarios. Kotlin is fully interoperable with Java, so their similarities far outweigh their differences when considering project requirements. 

Only when you consider the specific requirements of a particular project will you see those differences.

When Java Shines

Java is mature and has an extensive ecosystem, so it’s powerful for building large-scale applications across several platforms, such as enterprise software systems, web backends, and legacy Android applications. 

Its wealth of established libraries and frameworks, such as Spring and Hibernate, simplify complex development tasks. Java is often the safer choice for:

• Maintaining or extending existing large codebases
• Applications requiring heavy computational processing
• Projects where long-term stability is prioritized over rapid development

While sometimes seen as a drawback, the language’s verbose nature contributes to clearer code maintenance in large teams, where explicit code can reduce misunderstandings.

Where Kotlin Excels

Kotlin has quickly emerged as the preferred option for new Android projects, particularly those that aim to support modern devices with efficient operation. Its clear syntax can help save development time and improve code readability. Kotlin particularly stands out for:

• New projects where developer productivity is crucial
• Applications needing robust null safety to prevent crashes
• Cross-platform development through Kotlin Multiplatform (KMM)
• Apps targeting both newer and older Android devices

Kotlin’s coroutines offer greater efficiency for asynchronous programming than Java’s traditional method of managing threads, leading to improved code cleanliness and speed in I/O-intensive applications.

Making the Right Choice

The decision ultimately depends on your specific needs:

• For new projects with modern Android features, Kotlin is generally the better option
• When working with legacy systems or requiring maximum computational performance, Java may be preferable
• If cross-platform development is a priority, Kotlin’s multiplatform capabilities give it a clear advantage

While Kotlin represents the future of Android development, Java’s stability and proven track record ensure it remains relevant. Many successful projects use both languages together, leveraging each one’s strengths where they matter most.

What is the Future of Android development with Kotlin vs Java?

Currently, more and more businesses are moving towards Kotlin. Even though these companies call it their programming language for mobile app development, Kotlin is worth more than Java. At first, transforming your processes to a standard might seem daunting. But once you gain the power to control new features of Kotlin, developing apps will become easier. 

From a developer’s perspective, Java is still prioritized as a learning language for beginners. Java is the best option for anyone who wants to start coding from the basics. Compared to other programming languages, it has a relatively easy-to-understand syntax, is platform-independent, and is completely object-oriented.

Final Words

Which one, Kotlin or Java, is superior, and should you utilize it? What you require will determine the response to that inquiry. Kotlin may be the ideal option if you’re seeking a language with strong Google support because Android Studio 3 now supports Kotlin development. 

On the other hand, Java can be the best choice if you require speed or want an open-source project with more freedom (particularly in third-party libraries).

Are you ready to accelerate your brand using mobile apps? Whether you choose Kotlin or Java, Integrated IT Solutions can transform your ideas into reliable applications. Visit our services for your next big project!

FAQs

Should I Learn Java or Kotlin?

If you are learning to develop Android apps, Kotlin is a preferred programming language. But if you are starting as a beginner and have no knowledge of coding, then use Java.

What Should I Use for Android Development, Java, or Kotlin?

Both are considered reliable options for creating Android apps. However, Kotlin has recently outperformed Java in some places due to its precise syntax and advanced features, such as inline functions. 

Will Kotlin Replace Java in Android App Development?

That’s Right! Kotlin is better than Java in terms of code maintenance and reliability, making it easier for developers to drive productivity in app development.