Android 4.4 to 17: every version at a glance

This series has one note per Android release, from 4.4 KitKat (API 19, 2013) to Android 17 (API 37, 2026). Every note uses the same sections, so two versions compare side by side. Use the table to find a version, or the threads below it to follow one subject, such as permissions, across all eighteen.

All versions at a glance

The year is when the release reached its first devices. API 20 is missing because it existed only for watches, as Android 4.4W; the KitKat note covers it. From Android 13 on, the internal name is also the Build.VERSION_CODES constant, such as TIRAMISU.

Most rows have two kinds of change: those that reach every app on that version, and those that wait until an app targets its API level. Since 2018, Google Play has made apps adopt the second kind. New apps had to target API 26 from August 2018 and updates from November 2018, and the floor has risen every year since. From 2023 both deadlines fall on 31 August.

The threads that run through every version

Permissions

Until 5.1, every permission was granted at install. Android 6.0 split them into normal and dangerous: apps targeting API 23 ask for a dangerous one while they run, and users can switch permissions off for any app.

Each release after that narrowed what one answer gives away:

• 8.0. A grant no longer covers every permission of its group, for apps targeting API 26.
• 10. Location gets three answers, and background access becomes its own permission, ACCESS_BACKGROUND_LOCATION.
• 11. Camera, microphone and location offer “Only this time”. Two denials end the dialog, and unused apps targeting API 30 lose their grants.
• 12. The location dialog offers “Approximate”. Bluetooth scanning and connecting move to “Nearby devices” permissions such as BLUETOOTH_SCAN.
• 13. Notifications need POST_NOTIFICATIONS, and READ_EXTERNAL_STORAGE splits into READ_MEDIA_IMAGES, READ_MEDIA_VIDEO and READ_MEDIA_AUDIO.
• 14. Users can share only some photos (READ_MEDIA_VISUAL_USER_SELECTED). On Android 14, apps targeting below API 23 no longer install: Google said malware targets API 22 to dodge runtime permissions. Android 15 raised the floor to 24.
• 16. For apps targeting API 36, BODY_SENSORS gives way to granular health permissions such as READ_HEART_RATE.
• 17. Local network access needs ACCESS_LOCAL_NETWORK, and system pickers for contacts and location replace some permission requests.

Background work and battery

The rules for running in the background got stricter almost every year.

• 4.4. For apps targeting API 19, AlarmManager.set() is inexact and batched with other alarms.
• 5.0. JobScheduler holds work until its conditions are met (charging, unmetered network, idle) and runs jobs together.
• 6.0. Doze parks network access, wake locks and jobs on an idle phone, and App Standby does the same for apps the user has not touched.
• 7.0. Doze’s first level also applies in a moving pocket. CONNECTIVITY_ACTION stops reaching manifest receivers in apps targeting API 24.
• 8.0. For apps targeting API 26, an idle app’s background services are stopped, startService() from the background throws, and manifest receivers miss most implicit broadcasts.
• 9. App Standby Buckets (active, working set, frequent, rare) limit jobs, alarms and high-priority FCM messages, under Adaptive Battery.
• 12. Apps targeting API 31 cannot start a foreground service from the background, and exact alarms need SCHEDULE_EXACT_ALARM.
• 14. Every foreground service in an app targeting API 34 declares a type and its permission. Cached apps are frozen shortly after leaving the screen.
• 15. dataSync foreground services get 6 hours in every 24, for apps targeting API 35.
• 17. Audio playback needs a visible activity or a foreground service, for every app, and a process over its RAM-based memory limit is killed.

Storage

Android 4.4 closed shared storage first. Reading it needs READ_EXTERNAL_STORAGE, an app’s own Android/data folder needs no permission, and apps cannot write to an SD card outside their own folders. The storage access framework (ACTION_OPEN_DOCUMENT) lets the user pick a file instead.

• 5.0 adds ACTION_OPEN_DOCUMENT_TREE for whole folders, and 6.0 lets users format an SD card as internal storage.
• 7.0 throws FileUriExposedException when an app targeting API 24 shares a file:// URI. Share a content:// URI from FileProvider.
• 10 makes scoped storage the default for apps targeting API 29: they see only their own files and shared media. requestLegacyExternalStorage postpones it.
• 11 ignores that flag for apps targeting API 30. File managers and backup apps can ask for MANAGE_EXTERNAL_STORAGE, which Play reviews.
• 13 replaces READ_EXTERNAL_STORAGE with three media permissions and ships a photo picker that needs none. 14 lets the user pick which photos an app sees.

Security updates and platform hardening

• SELinux. Android 4.4 enforced it for a few system domains; Android 5.0 enforces it for every domain, vendor ones included.
• Monthly updates. In August 2015 Google promised Nexus devices a monthly security update, and the first public bulletin covered the Stagefright media flaws. Android 6.0 added Build.VERSION.SECURITY_PATCH, the date of the last patch.
• Encryption. The 6.0 CDD requires encryption on by default on devices with a secure lock screen and AES above 50 MiB/s. Android 7.0 brought file-based encryption, and Android 10 requires it on every device that launches with it.
• Verified Boot and updates. Android 7.0 enforces Verified Boot strictly, and the Pixel, on 7.1, was the first phone with A/B updates that install in the background.
• Treble. Android 8.0 put a stable vendor interface between the framework and the chip makers’ code. Devices launching with Android 9 can run a generic system image.
• Mainline. Android 10 updates system components through Google Play system updates. Android 11 added 12 modules, and Android 12 made ART one of them.
• Cryptography. Android 17 generates ML-DSA keys in the Keystore and pairs a post-quantum signature with a classical one in APK Signature Scheme v3.2.

Names

The dessert names were public and alphabetical through Android 9 Pie. Google and Nestlé announced the KitKat name together on 3 September 2013. For Android N, Google asked the public for suggestions, kept the choice, and announced Nougat.

On 22 August 2019 Google dropped the desserts. Sameer Samat wrote that they “weren’t always understood by everyone in the global community”: in some languages L and R sound the same, and pies are not a dessert everywhere. The names stayed in use inside the team: Quince Tart for 10, Red Velvet Cake for 11, Snow Cone for 12. 12L never had one; the code calls it S_V2.

From Android 13, the internal name is the SDK constant: TIRAMISU, UPSIDE_DOWN_CAKE, VANILLA_ICE_CREAM. After V, the alphabet started over with BAKLAVA for 16 and CINNAMON_BUN for 17, and their build IDs start with B and C.

Worth knowing

• AOSP comments. Build.java documents each constant, often with a joke. M reads M comes after L., N reads N is for ¯\_(ツ)_/¯., and 12L’s S_V2 quotes Henry V: “Once more unto the breach, dear friends, once more.”
• A sweet process. The Easter eggs of 4.4 and 6.0 run in a process named :sweetsweetdesserts.
• 12L says 12. On Android 12L, Build.VERSION.RELEASE returns 12, because the build sets PLATFORM_VERSION_LAST_STABLE := 12. Check SDK_INT >= 32, never the version string.
• Not Opera. Android 8.0 build IDs start with OPR, which appears in the user agent. Google warned that browser detection matching /OPR/ can mistake any browser for Opera.
• no.such.thing. In AOSP, Build.SERIAL is set by reading a property with that name. The function call stops compilers from inlining the value, so Android 9 can return "unknown" to apps targeting API 28.