Multithreading in Compose Multiplatform Web Apps

Mon, 02 Nov 2026 00:00:00 +0000

The standard way to work with multithreading and asynchronous code in Kotlin is to use the kotlinx.coroutines library.

To make code execution easier to manage, the library provides several standard dispatchers:

Dispatchers.Main — for working on the UI thread, if the platform has one.
Dispatchers.Default — for CPU-intensive work, such as calculations and data processing. Used by default when no dispatcher is specified.
Dispatchers.IO — for blocking I/O operations, such as file operations or blocking network calls.
Dispatchers.Unconfined — starts a coroutine on the current thread until its first suspension. After that, the coroutine may resume on a thread chosen by the suspending operation.

In Compose Multiplatform apps, application code usually starts running on Dispatchers.Main. So all blocking and heavy operations need to move to other threads to avoid blocking the UI.

Coroutines on terrakok

Multithreading in Compose Multiplatform Web Apps