Android 12: Material You, privacy dashboard

Android 12 is the release where the wallpaper picked the colors of the whole system. For users it brought Material You, a privacy dashboard and switches that cut off every app’s camera and microphone. For developers targeting API 31 it made android:exported and PendingIntent mutability mandatory, and it stopped foreground services from starting in the background.

At a glance

Google announced Android 12 with Developer Preview 1 on 18 February 2021. Beta 1 followed on 18 May at Google I/O, and Beta 4 reached platform stability on 11 August, freezing the APIs and app-facing behaviour. The three developer previews and five betas are the parts below this overview.

Google pushed the Android 12 source to AOSP on 4 October 2021. Phones waited two more weeks: the rollout started on 19 October, for the Pixel 3 and newer, the same day Google announced the Pixel 6 and Pixel 6 Pro. Google named Samsung, OnePlus, Oppo, realme, Tecno, Vivo and Xiaomi for later in the year. The first build, SP1A.210812.015, covered the Pixel 3 to the Pixel 5a.

The codename was Snow Cone. In AOSP the release branches are sc-dev and sc-release, the prefix the commits at the android-12.0.0_r1 tag merge into. On 4 October 2021 Dave Burke, Android’s VP of engineering, posted “A cool background to celebrate the launch of Android Snow Cone!”, which TechRadar and Android Central reported. The SDK constant stays S, and Google never used the name in its own release posts.

What it brought

• Material You. A new design language with larger controls, a redesigned notification shade and Quick Settings, and widgets with rounded corners.
• Dynamic color. The system builds a palette from the wallpaper and applies it to the lock screen, notifications, settings, widgets and apps that opt in. Apps read it through 65 new color resources, five palettes of 13 tones each (system_accent1_0 to system_neutral2_1000). Google shipped it on Pixel first.
• Splash screens. Every app gets a system splash screen on cold and warm starts, built from its icon and theme. The SplashScreen API customizes it with attributes such as windowSplashScreenAnimatedIcon.
• Stretch overscroll. Lists stretch and bounce at the edge instead of showing a glow.
• Scrolling screenshots. A screenshot can grow to capture a whole scrolling page. Apps can feed the scrolled content of a custom view to the system with ScrollCaptureCallback, set through View.setScrollCaptureCallback() or Window.registerScrollCaptureCallback().
• Power button. On Pixel, a long press of the power button opens Google Assistant, and the power menu moves to a button in Quick Settings. The smart home controls and Google Pay that Android 11 put in the power menu became Quick Settings tiles.
• Accessibility. A window magnifier zooms part of the screen and keeps the rest visible, and “Extra dim” lowers the screen below its minimum brightness.
• Rich content insertion. One callback, OnReceiveContentListener, receives images and other content from the clipboard, the keyboard or drag and drop.
• Graphics and media. RenderEffect blurs and filters a view in one call, AVIF images decode natively, and the system can transcode HEVC and HDR video to AVC for apps that cannot read it.
• Notifications. Notification.CallStyle for calls, animated images in messaging and big picture styles, and notification actions that require an unlocked device (setAuthenticationRequired()).
• Smaller additions. Rounded corner APIs (RoundedCorner), richer haptics (VibratorManager), haptics generated from an audio session (HapticGenerator), a Game Mode API, AppSearch, picture-in-picture that enters on its own (setAutoEnterEnabled()), and the chipset name in Build.SOC_MANUFACTURER and Build.SOC_MODEL.

Google’s developer post said Android 12 cut the CPU time used by core system services by 22%.

Android 12 (Go edition), for entry-level phones, followed. Google introduced it on 14 December 2021 for phones arriving in 2022. It said apps there launch up to 30% faster, unused apps hibernate automatically, and the privacy dashboard comes along.

Security and privacy

• Privacy dashboard. A Settings screen shows a timeline of which apps used location, camera and microphone in the past 24 hours. An app can explain each access with an activity guarded by START_VIEW_PERMISSION_USAGE that handles VIEW_PERMISSION_USAGE_FOR_PERIOD.
• Camera and microphone indicators. A status bar icon appears whenever an app uses either sensor. AOSP makes the indicators mandatory for all device makers.
• Camera and microphone toggles. “Camera access” and “Mic access” in Quick Settings turn the sensor off for every app. A blocked app gets a blank camera feed or silent audio, without an error. Emergency calls turn the microphone back on.
• Clipboard toast. The first time an app reads another app’s clip with getPrimaryClip(), the system shows “APP pasted from your clipboard”. getPrimaryClipDescription() does not trigger it.
• Private Compute Core. An isolated, open source part of the OS where Live Caption, Now Playing and Smart Reply process data on the device. Features inside it have no direct network access; model updates come through Private Compute Services.
• Overlays. Touches that pass through an obscuring window are blocked, apps can hide other apps’ overlays with HIDE_OVERLAY_WINDOWS, and preinstalled apps no longer get SYSTEM_ALERT_WINDOW automatically.
• Platform. ART becomes a Mainline module (com.android.art), so Google can update the runtime through Google Play system updates. Rust is supported for platform code. New phones ship the Generic Kernel Image, and Ars Technica called the Pixel 6 the first GKI phone. Users can also turn off 2G, and work profiles lose access to the IMEI and serial number.
• Crypto. The deprecated BouncyCastle algorithms, including every AES variant, are gone in favor of Conscrypt.

Permissions

• Approximate location. When an app asks for ACCESS_FINE_LOCATION, the dialog offers “Precise” or “Approximate”, next to the one-time options from Android 11. The app must request ACCESS_COARSE_LOCATION in the same call, or on some Android 12 releases the dialog does not appear at all.

• Nearby devices. BLUETOOTH_SCAN, BLUETOOTH_CONNECT and BLUETOOTH_ADVERTISE are new runtime permissions, shown to the user as “Nearby devices”, along with UWB_RANGING. They replace BLUETOOTH and BLUETOOTH_ADMIN for apps targeting 31. An app that never derives location from scans adds usesPermissionFlags="neverForLocation" and drops ACCESS_FINE_LOCATION.
• Exact alarms. For apps targeting 31, SCHEDULE_EXACT_ALARM is an app-op permission granted in the “Alarms & reminders” special access screen. Call canScheduleExactAlarms() before setting one; if the user revokes it, the app stops and its exact alarms are cancelled.
• Fast sensors. For apps targeting 31, the accelerometer, gyroscope and magnetometer are capped at 200 Hz through registerListener(). Higher rates need HIGH_SAMPLING_RATE_SENSORS, and with the microphone toggle off the cap applies anyway.
• Hibernation. For apps targeting 31, the permission auto-reset of Android 11 grows: an app the user has not opened for a few months also loses its jobs, alarms, push messages and cache. The switch is “Remove permissions and free up space” in App info.
• Updates without a prompt. An app store that declares UPDATE_PACKAGES_WITHOUT_USER_ACTION, a normal permission granted at install, can call setRequireUserAction(USER_ACTION_NOT_REQUIRED) on a PackageInstaller session and update apps without a confirmation dialog. It works only for apps it installed, or for itself, and on Android 12 only when the updated app targets API 29 or higher.

What changed for your app

All apps on Android 12

Apps targeting API 31

Without android:exported, the app does not install on Android 12: the build fails with a manifest merger error. A missing mutability flag fails at runtime, and lint flags it as UnspecifiedImmutableFlag.

The foreground service rule throws ForegroundServiceStartNotAllowedException. The exceptions include a high-priority FCM message, a tap on the app’s notification or widget, an exact alarm, BOOT_COMPLETED, and apps the user exempted from battery optimization.

Calling startForegroundService() anyway on the “no” branch is what throws the exception.

What lasted

• Material You and dynamic color remain Android’s design base, and the 65 system color resources are still the way apps read the palette.
• The Nearby devices group grew: Android 13 added NEARBY_WIFI_DEVICES, so Wi-Fi scanning no longer needs location either.
• Exact alarms tightened. Android 13 added USE_EXACT_ALARM for alarm and calendar apps and stopped pre-granting SCHEDULE_EXACT_ALARM to new installs of apps targeting 33.
• Hibernation stayed. From Android 13 the switch reads “Pause app activity if unused”.
• Foreground services kept narrowing: apps targeting Android 14 must declare a type for every one.
• The splash screen reached older devices through androidx.core:core-splashscreen, which brings it to API 23.
• ART as a module paid off. In 2023 Google said its ART updates reached all Android 12 and newer devices, with app startup up to 30% faster on some.
• Security patches ran until March 2025. That month’s Android Security Bulletin still lists 12 and 12L among the updated AOSP versions; from April 2025 the list starts at Android 13.

The point release that followed, Android 12L (API 32), reworked the system for large screens and has its own note in this series.

Worth knowing

• The Easter egg is an analog clock. Drag its hands to 12:00 and the next stage starts; the code logs “12:00 let’s gooooo”.

• The background then fills with bubbles drawn from the system accent palette, and the egg unlocks Paint Chips, a home screen widget that shows the dynamic color palette “in a manner similar to a set of paint samples from a hardware store”, as the AOSP string comment puts it.
• In AOSP the wallpaper-to-theme code sits behind a flag named Monet (isMonetEnabled() in SystemUI’s ThemeOverlayController). Ars Technica’s review reported Monet as the color system’s codename.
• The S constant in AOSP’s Build.java carries a one-word comment: S..