Event bus for Android and Java that simplifies communication between Activities, Fragments, Threads, Services, etc. Less code, better quality.
Clone or download


Hey, do have a minute for a quick survey on how we are doing with EventBus?


EventBus is a publish/subscribe event bus for Android and Java.


  • simplifies the communication between components
    • decouples event senders and receivers
    • performs well with Activities, Fragments, and background threads
    • avoids complex and error-prone dependencies and life cycle issues
  • makes your code simpler
  • is fast
  • is tiny (~50k jar)
  • is proven in practice by apps with 100,000,000+ installs
  • has advanced features like delivery threads, subscriber priorities, etc.

Build Status

EventBus in 3 steps

  1. Define events:

    public static class MessageEvent { /* Additional fields if needed */ }
  2. Prepare subscribers: Declare and annotate your subscribing method, optionally specify a thread mode:

    @Subscribe(threadMode = ThreadMode.MAIN)  
    public void onMessageEvent(MessageEvent event) {/* Do something */};

    Register and unregister your subscriber. For example on Android, activities and fragments should usually register according to their life cycle:

     public void onStart() {
     public void onStop() {
  3. Post events:

     EventBus.getDefault().post(new MessageEvent());

Read the full getting started guide.

Add EventBus to your project

Via Gradle:

implementation 'org.greenrobot:eventbus:3.1.1'

Via Maven:


Or download the latest JAR from Maven Central.

Homepage, Documentation, Links

For more details please check the EventBus website. Here are some direct links you may find useful:






How does EventBus compare to other solutions, like Otto from Square? Check this comparison.


Copyright (C) 2012-2017 Markus Junginger, greenrobot (http://greenrobot.org)

EventBus binaries and source code can be used according to the Apache License, Version 2.0.

More Open Source by greenrobot

ObjectBox (GitHub) is a new superfast object-oriented database for mobile.

Essentials (GitHub) is a set of utility classes and hash functions for Android & Java projects.

greenDAO (GitHub) is an ORM optimized for Android: it maps database tables to Java objects and uses code generation for optimal speed.

Follow us on Google+ or check our homepage to stay up to date.