The Typical Release Process

Not only has the release cadence slowed down, but it has normalized in the past several years. Starting with Android 5.0, we have had a fairly consistent pattern for when and how Google releases new major versions of Android.

Step #1: The First Developer Preview

In February or March, Google will ship a developer preview or beta release of the new version. Historically, this has been given a letter designation (e.g., 2019’s developer preview was Android Q, 2020’s is Android R). The first developer preview is often referred to as “DP1” for simplicity.

A developer preview includes:

• Explanations of changes to Android, including new features and new restrictions
• An SDK version based on the name that we can use for compileSdkVersion (e.g., android-R) and targetSdkVersion (e.g., 'R')
• An emulator that runs a version of Android that supports the new SDK
• Firmware images that can be loaded onto select Android devices (mostly some of Google’s Pixel devices) that allow those devices to run the preview version of Android

Early adopters can download these things and start experimenting with the changes.

Shortly after this release, the author of this book will start publishing blog posts about the new Android version, such as this post on Android R DP1. And, shortly after that, CommonsWare will have a new book for that new Android version, akin to 2019’s Elements of Android Q and 2020’s Elements of Android R.

Step #2: Additional Early Previews

Roughly once a month thereafter, Google will release another developer preview. This will contain updates to the same materials that were published as the previous developer preview. Notably, the updated versions will fix various bugs that were reported by early adopters… at least those bugs that are considered by Google to be bugs and not “working as intended”.

Step #3: Google I|O

Google holds their primary developer conference — Google I|O — in May. In recent years, the conference is held in the Shoreline Amphitheatre complex, just down the road from Google’s Mountain View offices. Google also livestreams many of the sessions on YouTube and publishes recordings of them afterwards.

Several of the Google I|O sessions will be about the new Android version. Usually, there is a “What’s New in Android” that covers all the major changes. And, usually, there are many dedicated sessions on individual new features or specific changes that developers need to take into account.

In 2020, Google I|O was cancelled on account of the COVID-19 pandemic.

Step #4: The Stable API Preview

A month or two after Google I|O, Google will ship a developer preview where the APIs defined in the Android SDK for this version will be considered final and should not be changing anymore.

Also, we will get official word of the next API level number, which is always the previous API level number plus one. For example, Android 10 was API Level 29, following on Android 9’s API Level 28. Also, we will be able to switch to these numbers for the compileSdkVersion and targetSdkVersion values for our projects.

Step #5: Shipping to Production

After that — where the timing has ranged from August to November — Google will ship the new Android version to the newer generations of Pixel devices. Other device manufacturers will start shipping updates to some of their devices in the coming months. A few devices beyond the Pixels may get updates rapidly, but usually manufacturers delay shipping OS updates by many months, if ever.

Sometime after this, the author of this book will start updating it for the new Android version, based on the material from the corresponding Elements book published earlier.

Step #6: New Official Hardware

Sometime around the production release date, Google will have a press event where they will unveil their new hardware for the year. This usually includes some new Pixel devices. These then tend to ship a few weeks after the launch event.

This is important because occasionally Android OS updates include features that are tied to specific hardware capabilities. If existing Pixels lack that hardware, these new Pixel devices might be the first ones where we can really use those new OS features.