API等級1：Android 1.0
API等級2：Android 1.1 Petit Four
API等級3：Android 1.5 Cupcake
API等級4：Android 1.6 Donut
API等級5：Android 2.0 Éclair
API等級6：Android 2.0.1 Éclair
API等級7：Android 2.1 Éclair
API等級8：Android 2.2 - 2.2.3 Froyo
API等級9：Android 2.3 - 2.3.2 Gingerbread
API等級10：Android 2.3.3-2.3.7 Gingerbread
API等級11：Android 3.0 Honeycomb
API等級12：Android 3.1 Honeycomb
API等級13：Android 3.2 Honeycomb
API等級14：Android 4.0 - 4.0.2 Ice Cream Sandwich
API等級15：Android 4.0.3 - 4.0.4 Ice Cream Sandwich
API等級16：Android 4.1 Jelly Bean
API等級17：Android 4.2 Jelly Bean
API等級18：Android 4.3 Jelly Bean
API等級19：Android 4.4 KitKat
API等級20：Android 4.4W
API等級21：Android 5.0 Lollipop
API等級22：Android 5.1 Lollipop
API等級23：Android 6.0 Marshmallow
API等級24：Android 7.0 Nougat
Android 5.0 Lollipop
- Support for 64-bit CPUs
- Recent activities screen with tasks instead of applications, up to a configured maximum of tasks per application
- Support for print previews.
- Material design style, bringing improvements to user interface.
- Project Volta improves battery life.
- Search Inside Settings
- Guest mode
- Audio input and output through USB devices
Android 4.4 KitKat
- Print Wherever, Whenever. Now you can print photos, documents, and web pages from your phone or tablet.
- Closed captioning Android now supports closed captioning and subtitles.
- Device management built-in, If you ever lose your device, you can find or wipe it with the Android Device Manager
- Infrared blasting on devices with an infrared (IR) blaster, Android now supports applications for remote control of TVs and other nearby devices.
- Optimizations for performance on devices with lower specifications, Low RAM device API.
- NFC Host Card Emulation for emulating smart cards.
- Refreshed interface with translucent status and nav bars on home screen & white status bar icons.
- Expanded functionality for Notification listener services.
- Public API for developing and managing text messaging clients, ability to specify a default SMS app.
- New framework for UI transitions.
- Storage access framework for retrieving content and documents from other sources.
- Sensor batching, Step Detector and Counter APIs.
- “Immersive” full screen mode, software buttons and status bar accessed with an edge swipe gesture.
- Audio tunneling, audio monitoring, loudness enhancer.
- Built-in screen recording.
- Native infrared blaster API
Android 4.3 Jelly Bean
- Virtual surround sound – enjoy movies from Google Play with surround sound on Nexus 7 (2013 edition) and other Nexus devices.
- Auto complete – just start touching numbers or letters and the dial pad will suggest phone numbers or names. To turn on this feature, open your phone app settings and enable “Dial pad auto complete.”
- OpenGL ES 3.0 – Android now supports the latest version of the industry standard for high performance graphics.
- Wireless Display for Nexus 7 (2013 edition) and Nexus 10 – project from your tablet to a TV.
- Additional language support – Android is now translated in Afrikaans, Amharic (አማርኛ), Hindi (हिंदी), Swahili (Kiswahili), and Zulu (IsiZulu).
- Hebrew, Arabic, and other RTL (right-to-left) – now supported in the home screen, settings, and Phone, People, and Keep apps.
- Easier text input – an improved algorithm for tap-typing recognition makes text input easier.
- Lower latency input for game pad buttons and joysticks.
- Location detection through WIFI – use WiFi to detect location without turning on WiFi all the time.
- Bluetooth Smart support (a.k.a. Bluetooth Low-Energy) – devices like Nexus 4 and Nexus 7 (2013 edition) are now Bluetooth Smart Ready.
- Bluetooth AVRCP 1.3 support – display song names on a car stereo.
- Disabled apps tab – check which apps are disabled in Settings > Apps.
- Restricted profiles – put your tablet into a mode with limited access to apps and content.
- Setup wizard simplification – getting started on Android is easier thanks to the ability to correct previous input, and because of streamlined user agreements.
- Faster user switching – switching users from the lock screen is now faster.
- Enhanced photo daydream – navigate through interesting albums.
Android 4.2 Jelly Bean
- Lock/home screen rotation support for the Nexus 7
- One-finger gestures to expand/collapse notifications
- Bug fixes and performance enhancements
- Photo Sphere panorama photos
- Keyboard with gesture typing
- Lock screen improvements, including widget support and the ability to swipe directly to camera
- Notification power controls
- “Daydream” screensaver, shows information when idle or docked
- Multiple user accounts (tablets only)
- Support for wireless display (Miracast)
- Accessibility improvements: triple-tap to magnify the entire screen, pan and zoom with two fingers. Speech output and Gesture Mode navigation for blind users.
- New clock app with built-in world clock, stop watch and timer
Photo Sphere全景拍照功能；
鍵盤手勢輸入功能；
改進鎖屏功能，包括鎖屏狀態下支持桌面掛件和直接打開照相功能等；
可擴展通知，允許用戶直接打開應用；
Gmail郵件可縮放顯示；
Daydream屏幕保護程序；
用戶連點三次可放大整個顯示頻，還可用兩根手指進行旋轉和縮放顯示，以及專爲盲人用戶設計的語音輸出和手勢模式導航功能等；
支持Miracast無線顯示共享功能；
Google Now現可允許用戶使用Gamail作爲新的數據來源，如改進後的航班追蹤功能、酒店和餐廳預訂功能以及音樂和電影推薦功能等。
Android 4.1 Jelly Bean
- Smoother playback of video and animations by:
- Vsync timing across all drawing and animation done by the Android framework, including application rendering, touch events, screen composition and display refresh
- Triple buffering in the graphics pipeline
- Enhanced accessibility
- Bi-directional text and other language support
- User-installable keyboard maps
- Expandable notifications
- Ability to turn off notifications on an app specific basis
- Shortcuts and widgets can automatically be re-arranged or re-sized to allow new items to fit on home screens
- Bluetooth data transfer for Android Beam
- Offline voice dictation
- New interface layout for tablets with smaller screens (closer resembling that of a phone)
- Improved voice search
- Improved camera app
- Google Wallet (for the Nexus 7)
- High resolution Google+ contact photos[citation needed]
- Google Now
- Multichannel audio
- USB audio (for external sound DACs)
- Audio chaining (also known as gapless playback)
Android 4.0 Ice Cream Sandwich
- Virtual buttons in the UI, in place of capacitive or physical buttons
- Separation of widgets in a new tab, listed in a similar manner to apps
- Easier-to-create folders, with a drag-and-drop style
- A customizable launcher
- Improved visual voicemail with the ability to speed up or slow down voicemail messages
- Pinch-to-zoom functionality in the calendar
- Integrated screenshot capture (accomplished by holding down the Power and Volume-Down buttons)
- Improved error correction on the keyboard
- Ability to access apps directly from lock screen
- Improved copy and paste functionality
- Better voice integration and continuous, real-time speech to text dictation
- Face Unlock, a feature that allows users to unlock handsets using facial recognition software
- New tabbed web browser, allowing up to 16 tabs
- Automatic syncing of browser with users’ Chrome bookmarks
- A new typeface family for the UI, Roboto
- Data Usage section in settings that lets users set warnings when they approach a certain usage limit, and disable data use when the limit is exceeded
- Ability to shut down apps that are using data in the background
- Improved camera app with zero shutter lag, time lapse settings, panorama mode, and the ability to zoom while recording
- Built-in photo editor
- New gallery layout, organized by location and person
- Refreshed “People” app with social network integration, status updates and hi-res images
- Android Beam, a near-field communication feature allowing the rapid short-range exchange of web bookmarks, contact info, directions, YouTube videos and other data
- Support for the WebP image format
- Hardware acceleration of the UI
- Wi-Fi Direct
- 1080p video recording for stock Android devices
統一了手機和平板電腦使用的系統，應用會自動根據設備選擇最佳顯示方式。
提升硬件的性能以及系統的優化，提升系統流暢度。
支持在系統中使用虛擬按鍵，該功能可以取代物理按鍵。
界面以新的標籤頁形式展示，並且將應用程序和其他內容的圖標分類。
更方便地在主界面創建文件夾，並且使用“一拖”、“一放”的操作方式。
一個定製的啓動器
改進的可視化語音郵件的能力，加快或減慢語音郵件。
在日曆中也可以使用多點觸控，進行縮放和拖拽操作。
Gmail離線搜索，兩行預覽，和新的任務欄。
與其他第三方微博、博客類應用程序的無縫連接，實時更新的內容會被展示在主界面上。
Gmail支持縮放操作，支持左拉、右拉進行查看。
增加截圖功能（可以同時按住電源鍵和音量向下鍵進行截圖操作）。
改進虛擬鍵盤可以產生的誤操作
在鎖屏狀態下也可以對用戶設置的某些應用程序進行操作
改進的複製、粘貼功能
更好的語音集成，實時錄音，文本聽寫等語音功能。
臉部識別進行鎖屏，可以通過臉部識別進行鎖屏。
新標籤頁模式的網頁瀏覽器，支持最大同時打開16個標籤頁。
自動同步用戶手機中的網頁書籤，可以在桌面版Chrome和其他Android設備中進行同步。
全新的現代化Roboto字體
內置流量監控功能，用戶可以對流量進行設置，超出設置流量時，手機會自動關閉上網功能，並且可以隨時查看已使用和未使用的流量，並且以報表的形式展現出來以幫助用戶瞭解使用情況。
能夠隨時關閉正在使用的應用程序
提升自帶的相機功能
內置圖片處理軟件
新的圖庫軟件
與其他第三方應用程序進行無縫銜接，用戶可以在任何界面看到自己需要的消息和圖像。
新的啓動畫面，主畫面右下角類似Tray的圖標，內有多個程序可運行。
Google Search Bar會設置在最上方
Apps/Widgets會類似Honeycomb模樣
增加支持硬件加速的功能
Wi-Fi直連功能
支持1080p視頻播放和錄製
Android 3.X Honeycomb
- Optimized tablet support with a new virtual and “holographic” user interface
- Added System Bar, featuring quick access to notifications, status, and soft navigation buttons, available at the bottom of the screen
- Added Action Bar, giving access to contextual options, navigation, widgets, or other types of content at the top of the screen
- Simplified multitasking – tapping Recent Apps in the System Bar allows users to see snapshots of the tasks underway and quickly jump from one app to another
- Redesigned keyboard, making typing fast, efficient and accurate on larger screen sizes
- Simplified, more intuitive copy/paste interface
- Multiple browser tabs replacing browser windows, plus form auto-fill and a new “incognito” mode allowing anonymous browsing
- Quick access to camera exposure, focus, flash, zoom, front-facing camera, time-lapse, and other camera features
- Ability to view albums and other collections in full-screen mode in Gallery, with easy access to thumbnails for other photos
- New two-pane Contacts UI and Fast Scroll to let users easily organize and locate contacts
- New two-pane Email UI to make viewing and organizing messages more efficient, allowing users to select one or more messages
- Support for video chat using Google Talk
- Hardware acceleration
- Support for multi-core processors
- Ability to encrypt all user data
優化針對平板 ；全新設計的UI增強網頁瀏覽功能 ；in-app purchases功能。
經過優化的Gmail電子郵箱 ；全面支持Google Maps ；將Android手機系統跟平板系統再次合併從而方便開發者；任務管理器可滾動，支持USB輸入設備（鍵盤、鼠標等） ；支持Google TV.可以支持XBOX 360無線手柄；widget支持的變化，能更加容易的定製屏幕widget插件。
支持7英寸設備；引入了應用顯示縮放功能。
Android 2.3 Gingerbread
- Updated user interface design with increased simplicity and speed
- Support for extra-large screen sizes and resolutions (WXGA and higher)
- Native support for SIP VoIP internet telephony
- Faster, more intuitive text input in virtual keyboard, with improved accuracy, better suggested text and voice input mode
- Enhanced copy/paste functionality, allowing users to select a word by press-hold, copy, and paste
- Support for Near Field Communication (NFC), allowing the user to read an NFC tag embedded in a poster, sticker, or advertisement
- New audio effects such as reverb, equalization, headphone virtualization, and bass boost
- New Download Manager, giving users easy access to any file downloaded from the browser, email, or another application
- Support for multiple cameras on the device, including a front-facing camera, if available
- Support for WebM/VP8 video playback, and AAC audio encoding
- Improved power management with a more active role in managing apps that are keeping the device awake for too long
- Enhanced support for native code development
- Switched from YAFFS to ext4 on newer devices
- Audio, graphical, and input enhancements for game developers
- Concurrent garbage collection for increased performance
- Native support for more sensors (such as gyroscopes and barometers)
增加了新的垃圾回收和優化處理事件；原生代碼可直接存取輸入和感應器事件、EGL/OpenGLES、OpenSL ES；新的管理窗口和生命週期的框架；支持VP8和WebM視頻格式，提供AAC和AMR寬頻編碼，提供了新的音頻效果器；支持前置攝像頭、SIP/VOIP和NFC（近場通訊）；簡化界面、速度提升；更快更直觀的文字輸入；一鍵文字選擇和複製/粘帖；改進的電源管理系統；新的應用管理方式。