How Zygote makes Android apps start faster?

Preloads common Android code to launch apps faster

Today, we are going to understand Zygote and why it is essential for faster Android app startup.

I’m Amit Shekhar from Outcome School, where I teach AI and Machine Learning, and Android.

Let’s get started.

Zygote is a special system process in Android. You can think of it like a “template” process in Android that helps apps start up really quickly.

When Android boots up, Zygote is one of the first processes that gets started. It preloads common Java classes, frameworks, and resources that nearly every Android app will need, things like the Android runtime, and core libraries. This preloading happens once at boot time.

When you tap an app icon, Android does not create a new process from zero. Instead, it copies (forks) the Zygote process. This copied process becomes your app process.

Because of this copy (fork):

• Common code is already loaded

• Memory can be shared

• Less work is needed

The app starts faster.

So, we get no repeated loading of the same framework code, lower memory usage, and faster app startup time.

Without Zygote, every time you open an app: This could take 2-3 seconds or more.

With Zygote, every time you open an app: Takes only a few hundred milliseconds.

Zygote speeds up app startup by preloading shared Android code once and reusing it for every app.

I teach these types of concepts at Outcome School and help you become a better software engineer.

Thanks

Amit Shekhar

Founder, Outcome School