(Newer OS)Android手机的(Android)较新操作系统升级应该会带来新功能和错误修复。但情况并非总是如此。有时，更新可能会带来比以前版本更多的错误。或者更糟糕的是，此更新甚至可能会破坏您设备上以前的Android版本中运行良好的功能。
在某些情况下，您可能会决定将设备降级到旧版本的操作系统，尤其是当旧版本在您的设备上运行良好时。
与 iOS 设备不同，完全有可能将Android 设备(Android device)恢复到旧版本的操作系统。许多(Many)制造商都有自己的工具来帮助您做到这一点。
使用 Odin 降级三星 Android 手机(Downgrade Samsung Android Phones Using Odin)
如果您有想要降级的三星 Android 手机，那么您很幸运。(Samsung Android phone)三星(Samsung)手机是少数几款可以轻松刷入旧版操作系统(operating system)的手机中的一部分。
您所需要的只是访问一台计算机，然后您就可以将您的设备降级。
为您的设备下载(Download)旧版本的库存固件(stock firmware)并将其保存到您的计算机。一个简单的谷歌搜索(Google search)将帮助您找到它。还将 Odin(Odin)闪存工具下载到您的计算机。
从库存固件和 Odin(stock firmware and Odin)中提取文件并启动Odin工具。单击工具中的PDA按钮并选择您提取的固件文件(firmware file)。
取消选择工具中的重新分区(Repartition)选项。选中(Checkmark)工具中的Auto Reboot和F. Reset Time选项。
关闭您的设备。同时按住降低音量(Volume Down)、主页(Home)和电源(Power)按钮几秒钟。询问时，按提高音量(Volume Up)，您的手机将重新启动进入下载模式(download mode)。
使用USB 数据线(USB cable)将手机连接到计算机。然后在Odin中单击开始(Start)，它将开始在您的手机上刷新库存固件文件。(stock firmware file)
文件刷新后，您的设备将重新启动。当手机启动时(phone boots-up)，您将使用旧版本的Android 操作系统(Android operating)。
使用 Fastboot 降级 Google Pixel 手机(Downgrade Google Pixel Phones With Fastboot)
Google为您提供Nexus 和 Pixel 设备(Nexus and Pixel devices)的出厂图片。您可以在设备上刷新这些图像以返回旧版本的Android 操作系统(Android OS)。
请记住，以下过程将清除您设备上的所有数据。
从Google(Google)下载您想要在设备上使用的版本的出厂映像(factory image)。下载文件后解压缩。此外，下载Fastboot并将其文件提取到您提取图像文件的同一文件夹中。
在您的手机上，前往Settings > System > Developer options并启用OEM 解锁(OEM unlocking)和USB 调试(USB debugging)。
使用USB 数据线(USB cable)将手机连接到计算机。打开图像文件所在的文件夹，按住Shift 键(Shift)，在空白处单击鼠标右键，然后选择在此处打开命令窗口(Open command window here)。
在窗口中输入以下命令，然后按 Enter(Enter)。它会将您的设备重新启动到引导加载程序模式(bootloader mode)。
adb 重启引导加载程序(adb reboot bootloader)
现在运行以下命令来解锁手机的引导加载程序。您会在手机上收到提示，因此请接受。
fastboot刷机解锁(fastboot flashing unlock)
引导加载程序解锁后，输入以下命令开始在手机上刷新库存固件。(stock firmware)这需要几分钟。
闪现(flash-all)
(Relock)通过运行以下命令重新锁定引导加载程序。
fastboot刷机锁(fastboot flashing lock)
打开手机电源，您将在设备上使用您选择的Android 操作系统(Android OS)版本。
使用 Flashtool 降级 Sony Android 手机(Downgrade Sony Android Phones Using Flashtool)
(Sony)借助 Flashtool 实用程序，(Flashtool utility)索尼手机也很容易降级。它使您可以刷新设备上的库存固件(stock firmware)，从而将设备降级到您选择的固件版本。
(Download)将Sony 手机(Sony phone)和Flashtool的库存固件(stock firmware)下载到您的计算机。在您的计算机上安装 Flashtool 。(Install Flashtool)
复制.ftf 固件文件并将(.ftf firmware file and paste)其粘贴到C:\Flashtool\firmwares文件夹中。
启动Flashtool，单击顶部的雷声图标，然后选择(thunder icon)Flashmode。
在以下屏幕上选择您的固件文件，选中(firmware file)擦除(Wipe)部分中的所有选项，然后点击底部的Flash 。
关掉你的手机。按住降低音量(Volume Down)并使用数据线将手机连接到计算机。该工具将自动启动闪存程序。
使用该工具刷新手机后重新启动手机。
使用 LG Flash 工具降级 LG Android 手机(Downgrade LG Android Phones Using LG Flash Tool)
如果您要降级LG 手机(LG phone)，则不需要运行任何命令或类似的东西。只需(Simply)下载库存固件(stock firmware)和工具，一切就绪。
这是如何做：
(Download)在您的计算机上下载您喜欢的Android 版本(Android version)和LG Flash Tool的库存ROM 。
关闭手机。将手机连接到计算机，同时按住手机上的提高音量(Volume Up )按钮。它会将您的手机重新启动到下载模式(download mode)。
在您的计算机上启动LG Flash Tool并选择以下选项。然后单击CSE Flash选项。
选择类型(Select Type)– CDMA
PhoneMode – DIAG
选择 KDZ 文件(Select KDZ file)–从您的计算机中选择库存ROM 文件(ROM file)
在以下屏幕上点击开始。(Start)
当您被要求选择您的国家和语言(country and language)时，不要选择任何内容并单击(t select anything and click)“确定(OK)” 。
刷入股票ROM后，您的手机将恢复为旧版本的Android 操作系统(Android OS)。
降级其他安卓设备(Downgrade Other Android Devices)
正如您在上述方法中所见，要恢复到旧版Android的过程通常需要您下载库存ROM和用于在设备上刷新ROM的工具。刷入ROM后，您将完全恢复到您选择的Android版本。
对于我们上面没有列出的手机，您可以轻松地从Google获取(Google)库存固件(stock firmware)文件和刷机工具。然后，只需在工具中加载ROM 文件(ROM file)，就可以在手机上刷入它了。
结论(Conclusion)
降级Android 手机(Android phone)基本上意味着在您的设备上刷新旧版本的Android 操作系统(Android OS)。一旦它被刷新，您就可以运行在较新版本中无法运行的应用程序，并且还可以享受在较新的(t work)Android版本中已损坏且不再适用的任何其他应用程序。
How to Downgrade Your Android OS Version
Newer ОS upgrades for your Android phones are supposеd to bring new features and bug-fixes. But that isn’t alwаys the case. Sometimes, an update may bring in mоrе bugѕ than the previous version had. Or worse, the update may even break the features that worked just fine іn the previous Android versions on your device.
These are some of the occasions where you may decide to downgrade your device to an older version of the OS, especially when that older version worked perfectly fine on your device.
Unlike iOS devices, it’s totally possible to get an Android device back to an older version of the OS. Many of the manufacturers have their own tools to help you do it.
Downgrade Samsung Android Phones Using Odin
If you have a Samsung Android phone that you wish to downgrade, you’re in luck. Samsung phones are some of the few phones that can be easily flashed with an older version of the operating system.
All you need is access to a computer and you can get your device downgraded.
Download an older version of the stock firmware for your device and save it to your computer. A simple Google search will help you find it. Also download the Odin flash tool to your computer.
Extract files from both stock firmware and Odin and launch the Odin tool. Click on the PDA button in the tool and select your extracted firmware file.
Deselect the Repartition option in the tool. Checkmark both Auto Reboot and F. Reset Time options in the tool.
Power off your device. Press and hold down Volume Down, Home, and Power buttons together for a few seconds. When asked, press Volume Up and your phone will reboot into the download mode.
Connect your phone to your computer using a USB cable. Then click on Start in Odin and it’ll start flashing the stock firmware file on your phone.
Once the file is flashed, your device will reboot. When the phone boots-up, you’ll be on an older version of the Android operating system.
Downgrade Google Pixel Phones With Fastboot
Google provides you with the factory images for your Nexus and Pixel devices. You can flash these images on your device to go back to an older version of the Android OS.
Keep in mind the following procedure will wipe off all the data on your device.
Download the factory image of the version you want on your device from Google. Extract the file when it has downloaded. Also, download Fastboot and extract its files to the same folder where you extracted the image files.
On your phone, head to Settings > System > Developer options and enable OEM unlocking and USB debugging.
Connect your phone to your computer using a USB cable. Open the folder where your image files are, hold down Shift, right-click anywhere blank, and select Open command window here.
Type in the following command into the window and hit Enter. It’ll reboot your device into the bootloader mode.
adb reboot bootloader
Now run the following command to unlock your phone’s bootloader. You’ll get a prompt on your phone so just accept that.
fastboot flashing unlock
Once the bootloader’s unlocked, type in the following command to start flashing the stock firmware on your phone. It’ll take a few minutes.
flash-all
Relock your bootloader by running the following command.
fastboot flashing lock
Power on your phone and you’ll be using your chosen version of the Android OS on your device.
Downgrade Sony Android Phones Using Flashtool
Sony phones are also easy to downgrade thanks to the Flashtool utility. It lets you flash the stock firmware on your device which in result downgrades the device to your chosen firmware version.
Download the stock firmware for your Sony phone and Flashtool to your computer. Install Flashtool on your computer.
Copy the .ftf firmware file and paste it into the C:\Flashtool\firmwares folder.
Launch Flashtool, click on the thunder icon at the top, and select Flashmode.
Select your firmware file on the following screen, checkmark all options in the Wipe section, and hit Flash at the bottom.
Turn off your phone. Hold down Volume Down and connect your phone to your computer using a cable. The tool will automatically start the flash procedure.
Restart your phone when it’s been flashed with the tool.
Downgrade LG Android Phones Using LG Flash Tool
If you’re downgrading an LG phone, you don’t need to run any commands or anything like that. Simply download the stock firmware and a tool and you’re all set.
Here’s how:
Download the stock ROM for your preferred Android version and LG Flash Tool on your computer.
Power off your phone. Connect the phone to your computer while holding down the Volume Up button on your phone. It’ll reboot your phone into the download mode.
Launch the LG Flash Tool on your computer and select the options as the following. Then click on the CSE Flash option.
Select Type – CDMA
PhoneMode – DIAG
Select KDZ file – select the stock ROM file from your computer
Hit Start on the following screen.
When you’re asked to choose your country and language, don’t select anything and click on OK.
When the stock ROM is flashed, your phone will be back to an older version of the Android OS.
Downgrade Other Android Devices
As you can see in the above methods, the procedure to get back to an older version of Android usually requires you to download a stock ROM and a tool to flash the ROM on your device. And when the ROM is flashed, you’re fully back to your chosen version of Android.
For the phones that we haven’t listed above, you can easily grab the stock firmware files and the flashing tools from Google. Then, simply load the ROM file in the tool and you’re ready to flash it on your phone.
Conclusion
Downgrading an Android phone basically means flashing an older version of the Android OS on your device. Once it’s flashed, you can run the apps that don’t work in newer versions and also enjoy anything else that got broken and no longer works in newer Android builds.
