Which language?

Java or Kotlin?

A language for an Android app is usually one of these two. Kotlin is shorter. Java still stands in older examples.

A new app usually starts with Kotlin.
If you know Java, you can read an old project. Kotlin does not erase it.
Both run on the same phone. One does not throw the other out.
Turning an HTML page into an APK is not learning this language. Java or Kotlin is needed when you write your own code inside.
A game often takes another road. An ordinary app is the answer to this question.

If you do not know either, start with Kotlin. If the old code is Java, read that too.

Python or JavaScript?

Is Python still worth learning in 2026?

About this tool

Choosing between Java and Kotlin is essential when building an Android app. Kotlin features shorter syntax and is standard for new apps. Java still stands in older examples, but both run on the same device and neither replaces the other entirely.

If you know neither, start with Kotlin. If legacy code is in Java, read that too. Turning an HTML page into an APK is not learning these languages; Java or Kotlin is required when you write your own code inside.

How to use it

Decide whether to use Java or Kotlin.
Set up your development environment.
Learn the basic syntax rules.
Write your first app code.

Common uses

Starting a brand new Android application.
Reading and maintaining older Java projects.
Building standard mobile app logic.
Running different codebase parts on the same phone.

Frequently asked questions

Which language should I pick first?

If you do not know either language, it is best to start with Kotlin for new apps.

Is Java completely useless now?

No, Java still stands in older examples, and knowing it helps you read legacy code.

Does converting HTML to APK count as learning these languages?

No, turning an HTML page into an APK is not learning this language; Java or Kotlin is needed for custom code.