Android Academy · Lesson

Notification Channels

Group notifications by importance.

Notification Channels is a free Android Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Android Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

Notification Channels

Since Android 8.0 (API 26), every notification must belong to a channel. Channels group related notifications and let users control them individually in system Settings.

Why Channels Exist

Channels give users fine-grained control. Instead of a single on/off switch for the whole app, users can mute "Promotions" while keeping "Messages" loud. This reduces notification fatigue.

Channels Are Required

On API 26 and above, posting a notification without a valid channel simply does nothing. You must create the channel before you post the first notification to it.

Importance Levels

Each channel has an importance that sets its default behavior:

IMPORTANCE_HIGH: makes sound and shows as a heads-up banner
IMPORTANCE_DEFAULT: makes sound
IMPORTANCE_LOW: no sound
IMPORTANCE_MIN: no sound, minimized

Creating a Channel

Build a NotificationChannel with an id, a user-visible name, and an importance.

val channel = NotificationChannel(
    "messages",
    "Messages",
    NotificationManager.IMPORTANCE_HIGH
).apply {
    description = "Chat messages from your contacts"
}

Registering With the System

Register the channel once with the NotificationManager via createNotificationChannel. Creating it again with the same id is safe and harmless.

val manager = context.getSystemService(NotificationManager::class.java)
manager.createNotificationChannel(channel)

Create Channels Early

A good place to create channels is in your Application.onCreate, so they exist before any code path tries to post a notification.

class MyApp : Application() {
    override fun onCreate() {
        super.onCreate()
        createNotificationChannels()
    }
}

Channel IDs Are Stable

The channel id is what you reference when posting notifications. Pick stable ids and keep them in constants so the builder and the channel always match.

object Channels {
    const val MESSAGES = "messages"
    const val PROMOTIONS = "promotions"
}

Users Own the Settings

After creation, the user controls the channel. If they lower its importance or mute it, your code cannot override that. You can only set the initial importance at creation.

Channel Groups

For apps with many channels, NotificationChannelGroup organizes them into sections in Settings, for example grouping all "Team A" and "Team B" channels separately.

Pre-API-26 Compatibility

On devices below API 26 there are no channels; the channel id is simply ignored. Using NotificationCompat lets the same code work across versions safely.

Quick Check

Test your understanding of notification channels.

Recap

You learned notification channels:

API 26+ requires every notification to have a channel
Importance levels set default sound and heads-up behavior
Create with NotificationChannel and register via createNotificationChannel
Create channels early; users ultimately control their settings

Next: building a notification.

Frequently asked questions

Is the “Notification Channels” lesson free?

Yes — the full text of “Notification Channels” is free to read here on the web, and the Android Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Android Academy course, upgrade to CoddyKit PRO.

What will I learn in “Notification Channels”?

Group notifications by importance. You practise Android Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Android Academy?

No prior experience is required. Android Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Notification Channels” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Android Academy lesson?

Yes. Every Android Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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