Users of flagship devices from Samsung often face a paradoxical situation: having powerful hardware, they are forced to put up with software redundancy. The shell One UI, although it has become much lighter in recent years, still contains many pre-installed services that cannot be removed using standard methods. That is why the request “how to install pure Android on a Samsung” remains one of the most popular among mobile technology enthusiasts.
The process of replacing proprietary firmware with a stock version Android (the so-called AOSP) or installing a custom assembly requires a deep understanding of security architecture. Android. Unlike devices Google Pixel or Xiaomi, smartphones of the Korean giant have specific limitations, such as Knox and a locked bootloader in some regions. Before taking radical actions, it is necessary to assess the risks and prepare tools.
It is worth noting right away that the concept of “pure Android” on devices Samsung can be interpreted in two ways. This can be official stock firmware without unnecessary applications (which is technically still based on the kernel One UI) or full-fledged custom firmware like LineageOS, completely devoid of proprietary layers. The choice of path depends on your model and your willingness to sacrifice the warranty and some camera functions for the sake of performance.
Preparing the device and unlocking the bootloader
The first and most critical step is unlocking the bootloader (Bootloader). On modern devices Samsung this procedure is irreversible from the point of view of the counter Knox. Once you flip the switch in the developer menu, the physical fuse inside the chip will trip and the warranty on the software part will be voided forever. Some banking applications and services like Samsung Pay will stop working correctly even after returning to the factory state.
First, you need to activate developer mode. Go to your phone settings, find the “About phone” section and quickly tap “Build number” seven times. After this, a new section “Developer Options” will appear in the main menu. Inside it, find the “OEM Unlock” item and activate it. If this item is missing or inactive, your device may be locked to a specific carrier or the firmware region does not support this feature.
⚠️ Attention: Unlocking the bootloader on Samsung devices automatically performs a full data reset (Factory Reset). All your photos, contacts and apps will be permanently deleted. Be sure to make a full backup to an external drive or to the cloud before starting the procedure.
After enabling the option, you will need to put your smartphone into a special download mode. Turn off the device completely. Then hold down the Volume Down and Power buttons at the same time (on models without a physical Home button). When the warning screen with the logo Android and the words “Warning” appears, press the volume up button once to confirm entering the mode Download Mode. It is in this state that the phone is ready to receive new system images.
☑️ Preparing for flashing
Necessary software and drivers for PC
To interact with the phone at a low level, you will need a computer running Windows. Although there are alternatives for Linux and macOS, the main tool - the app Odin - works most stably in the Windows environment. You will need to download the latest current version of the utility, for example, Odin3 v3.14.4 or later, as older versions may not recognize modern data transfer protocols.
A critical element is installing the correct drivers. Without drivers Samsung USB the computer will not see the phone in Download Modemode, and the process of writing the firmware will not begin. It is recommended to install the package Samsung USB Driver for Mobile Phones officially from the developer's website. After installing the drivers, check in the “Device Manager” that when you connect the phone in boot mode, a device appears with the name Android Phone or Samsung Mobile USB Serial Device without exclamation marks.
You will also need the firmware file itself. To install pure Android, custom images are most often used, which can be found on specialized forums such as 4PDA or XDA Developers. However, if your goal is simply a “clean” look of the official system, you can use the service to download the original software, and then manually remove unnecessary components via. Firmware files usually have the extension SamFw or Frija to download the original software, and then manually remove unnecessary components via ADB. Firmware files usually have the extension .tar or .tar.md5.
Use the original USB cable that came with your smartphone and connect it directly to the motherboard ports on the back of the PC. Connecting through the front panel of the case or cheap extension cables often leads to data transfer errors and “bricking” the device.
The process of installing firmware via Odin
Run the app Odin as administrator. The utility interface may seem overloaded, but for a basic installation we only need a few fields. Connect the switched off smartphone in Download Modemode to the computer. The message Added!should appear in the app log (bottom window), and one of the squares in the upper left corner (usually ID:COM) should be highlighted in blue or yellow. This is a signal of a successful connection.
Next you need to distribute the firmware files to the appropriate slots. In custom firmware, everything is often packaged into one file, which is loaded into the field AP (or PDA in older versions). If you are using the official firmware, unpacked into four parts, distribute them like this: a file named BL in the field BL, AP in the field AP, CP (modem) in the field CP and CSC in the field CSC. Using a file HOME_CSC will allow you to save the data, but for a clean installation it is better to use a regular one CSC, which will format the data section.
It is important to check the settings of the tab Options. Make sure that the checkboxes are only opposite Auto Reboot and F. Reset Time. The option Re-Partition must be unchecked if you are not using a special file .pitas enabling it without a corresponding file may irreversibly damage the memory partition table. After checking all the parameters, click the Startbutton. The process will take from 2 to 10 minutes depending on the size of the firmware and the speed of the USB port.
| Slot in Odin | File type | Description of contents | Responsibility |
|---|---|---|---|
BL |
Bootloader | Bootloader, system startup | Required |
AP |
System | Android kernel, system applications, interface | Required |
CP |
Modem | Radio module, communication, Wi-Fi, Bluetooth | Recommended |
CSC |
Region | Region settings, code countries, data reset | Required |
USERDATA |
Data | Preinstalled user files | Not used |
What to do if Odin is frozen at the "NAND Write Start" stage?
If the recording process is stuck and does not move for more than 5 minutes, do not panic. Often this is a false freeze. Wait a couple more minutes. If progress does not appear, force restart the phone (by holding Volume Down + Power), reconnect the cable and try again. Make sure that the antivirus is not blocking the connection.
Features of installing custom ROMs (LineageOS, Pixel Experience)
If the standard firmware is not satisfactory and you want to get a real Pixel Experience or LineageOS, the procedure becomes more complicated. After unlocking the bootloader, you will need to install a custom recovery, most often this TWRP (Team Win Recovery Project). The official version of TWRP for your model can be found on their website. The recovery file (usually .img) is flashed through Odin into the slot AP, but before that in the Odin settings you need to uncheck Auto Reboot.
After flashing the recovery image, the phone must be immediately switched to recovery mode manually so that the standard system does not overwrite TWRP back to stock recovery. In TWRP mode you get full access to the file system. Here you need to run the command Wipe -> Advanced Wipe and select partitions Dalvik / ART Cache, System, Data and Cach. This is a critical step to prevent conflicts between the old file system One UI and the new custom structure ROM.
Then, through the menu Install in TWRP, the archive with custom firmware downloaded earlier is selected. The installation process is similar to installing applications, but at the system level. Once the installation is complete, the system will prompt you to clear the Dalvik cache. Agree and reboot your device. The first launch of pure Android can take up to 10 minutes, as the system optimizes applications for the new environment.
Problems with security and functions of Samsung Knox
You should understand that installing any unverified firmware or unlocking the bootloader triggers the bit eFuse in the processor. The counter value Knox changes from 0x0 to 0x1. This is a physical change that cannot be rolled back programmatically. The consequences of this action affect not only the warranty. Security features that depend on the trusted execution environment no longer work.
In particular, you will lose access to Samsung Pay and Samsung Pass. These services require verified system integrity to process payments and store biometric data. There may also be problems with the operation of the Secure Folder application (Secure Folder). Some banking applications that use strict environmental integrity checks may also refuse to launch, although this problem can often be circumvented using root-hiding tools such as Magisk and module Play Integrity Fix.
⚠️ Attention: After the Knox flag is triggered, data encryption may work in a less secure mode. Do not store critical confidential information on such a device without additional means of protection, as the theoretical vulnerability of the system increases.
In addition, the camera on custom firmware often works worse than on the stock one. This is due to the fact that image processing algorithms from Samsung are proprietary and closed. Developers of custom ROMs are forced to use ports GCam (Google Camera), which cannot always interact correctly with specific sensors and optical stabilization of specific models Samsung.
Optimization and removal of system debris without flashing
If the risk of a complete flashing seems too high to you, there is an alternative way - “lightening” the system through ADB (Android Debug Bridge). This method allows you to remove most of the pre-installed applications Samsung and Googlethat cannot be removed through the settings without affecting the system partitions and without disrupting the operation of Knox. To do this, you need to enable USB debugging in the developer menu and connect the phone to the PC.
Using the console utility adb, you can send commands to disable packages. For example, the command adb shell pm uninstall -k --user 0 com.samsung.android.bixby.agent will turn off the Bixby voice assistant. There are many ready-made lists of commands and graphical shells, such as Universal Android Debloaterthat simplify this process by providing a convenient interface for selecting components to remove.
This approach gives an effect close to pure Android: frees up RAM, reduces the background load on the processor and increases battery life. At the same time, you retain all the advantages of the branded camera, connection stability and operation of all banking applications. This is the most balanced option for most users who want to get rid of intrusive software.
Using ADB to remove system applications is the “golden mean”. You get a clean system without unnecessary junk, while maintaining the warranty, Samsung Pay functionality and the quality of the standard camera.
Is it safe to install custom firmware on a new Samsung?
Installing custom firmware on new models is associated with a high risk. New processors and cameras require specific drivers, which are often missing from unofficial builds in the first months after the device is released. This may result in the camera not working, the communication module malfunctioning, or the battery draining quickly. It is recommended to wait for the ROM to be stabilized by community developers.
Is it possible to return the warranty after installing pure Android?
Formally, you can return the device to its original state in terms of software by flashing the official firmware via Odin. However, the physical Knox counter remains toggled. Service centers may refuse warranty repairs if they find traces of tampering with the software or a triggered security flag, especially if the failure is related to the software or motherboard.
Why does the fingerprint not work after firmware?
On many modern Samsung devices, biometric data is stored in encrypted form, the keys to which are tied to a specific instance system and bootloader. When you change the firmware or reset the data partition, these keys are lost. In custom firmware, biometrics support may not be fully implemented or require additional configuration via the terminal.
Do you need to root your phone to install pure Android?
No, obtaining superuser rights (Root) is not a prerequisite for installing custom firmware. An unlocked bootloader is enough. Moreover, many modern custom ROMs (for example, LineageOS) come without root access by default for security reasons. You can get them later by installing Magisk, if necessary.