Do you want to install any Custom ROM on your Samsung Galaxy S21 Ultra? then we will guide you to install ROM listed below. You must be aware that you are using an Android device. Well, the biggest advantage of using an Android device is that you can customize and develop your ROM.
So let’s begin with the phone’s configuration:
Samsung Galaxy S21 Ultra Specifications
- The phone was released on 14th January 2021
It comes with a 6.80-inch display with a resolution of 1440×3220 pixels.
- It packs a quad-camera of 108MP + 12MP + 10MP + 10MP with a front camera of 40MP
- The phone is powered by Samsung Exynos 2100 processor with 12GB RAM and 128GB of storage.
- Lastly, the phone is powered by a 5000mAh battery and runs on Android 11.
- Display: 6.8 inches AMOLED (3200 x 1400); 10 to 120Hz
- CPU: Snapdragon 888
- RAM: 12GB, 16GB
- Storage: 128GB, 256GB, 512GB
- Rear cameras: 108MP wide (f/1.8), 12MP ultra wide (f/2.2), 10MP telephoto (3x zoom, f/2.4), 10MP telephoto (10x zoom, f/4.9), laser AF sensor
- Front camera: 40MP (f/2.2)
- Video: 8K 30 fps/4K 60 fps
- Battery: 5,000 mAh
- Battery life: 11 hours 25 min (60Hz), 10:07 (adaptive)
- Wireless: 5G, Wi-Fi 6E, UWB
- Size: 6.5 x 2.97 x 0.35 inches
- Weight: 8.08 ounces
What is Stock ROM?
Whenever you purchase a new Android device is comes with a pre-installed ROM or stock firmware. The ROM has limited functionalities which are defined by the manufacturer and it defers according to the manufacturer. So it is the official ROM that is designed particularly for that specific device. These operating systems generally offer some standard customizations and some other device-specific support.
What is Custom ROM?
Custom ROM is an unofficial version of the OS
Android is an open-source platform that can be used by any developer to customize to build their own operating system for Android phones and tablets. The final customized operating system or Home built application is known as Custom ROM. Android comes with a kernel that makes it a fully standalone OS. Some developers in the Android community are customizing the Android OS by removing all unnecessary garbage apps and creating a pure Android experience for users.
This Custom ROM is updated regularly by the community and developers. Also, they fix all the bugs related to the operating system. So the Custom ROM is a gateway to experience the latest Android even if it is not supported on your device. We have listed some advantages and disadvantages of using a Custom ROM on your device, so please read them carefully before performing any actions on your phone, and make sure to take a complete backup of your device.
Advantages of using a Custom ROM
- The major advantage of using or installing any Custom ROM is that you can upgrade your phone to the latest version of Android.
- You get a clean experience of pure Android without any extra customizations
- It can enhance the security, reliability, and user interface of the device.
- You’ll get Administrate Root access by default
- A Custom ROM can help you to get some advanced features and functions on your phone.
- Afterall the smartphone is more about software and less of hardware
Disadvantages of using a Custom ROM
- The warranty of your Samsung Galaxy S21 Ultra will be void
- An unstable version of Custom ROM can brick your device so make sure that you are using an Authorised or genuine guide.
- After migrating to the Custom OS you will not be able to get OTA updates.
- Absence of Google Apps, Although, you can install GApps manually
Best Custom ROM for Samsung Galaxy S21 Ultra
Here are the best custom ROMs available for your Samsung Galaxy S21 Ultra. Once TWRP recovery is installed on your computer you can start installing any Custom ROM on your device from the list down below.
1. Android 11
Android 11 is similar to Android 10 with the latest technology and many features. This is a more polished version that supports features such as Chat bubbles, Notification history, Conversation notifications, screen recorder, new media controls, smart device controls, one-time permission, improved dark theme with the scheduling system, app suggestions, wireless android auto
2. Lineage OS
LineageOS was born after the death of CyanogenMod due to conflicts within the company. The new fork of CyanogenMod is now called LineageOS (A similar Open-source operating system for Android users). It will be the continuation of the project and will provide updates and more features continuously in the future.
Lineage OS is an open-source Android operating system. It is a popular OS that is the successor of CyanogenMod, one of the most popular custom ROM for Android. After the shut down of the CyanogenMod project, LineageOS was launched for its fans. The main advantage of using LineageOS is that it can be used without installing any Google apps with some standard customizations included.
It is the best Custom ROM available for Android devices. Lineage ROM for Samsung Galaxy S21 Ultra comes with a lot of features such as Customizable Status bar, Nav Bar color, Resizing Navbar, and customization, Quick Toggle feature, and other features.
3. AOSPExtended ROM
AOSP Extended is an AOSP based ROM that provides stock UI/UX experience with useful customizations on any Android device. AOSP ROM-based device provides a very smooth experience. The source code of AOSPExtended ROM provides various cherry-picked commits from multiple other projects. They have promised to bring new features and updates every year to make it a very successful custom OS for your OnePlus 7T. AOSPExtended ROM provides other features for the Status bar, Notification panel, QS Tiles, navigation bar, lock screen, and system options.
More features are listed on their blog.
4. CrDroid ROM
CrDroid OS is a new custom ROM based on AOSP/ Lineage OS built from scratch by adding customization options from AOSPA, Lineage, SlimROM. It offers a great simple, customizable, and secure experience to its users. CrDroid OS and many other great ROMs are out there. The ROM brings a lot of customization options along with a Pure Android Experience.
5. Resurrection Remix
Resurrection Remix ROM is a full-featured, reliable ROM that incorporates the greatest aspects of open source ROMs, and is a perfect fit for your Samsung Galaxy S21 Ultra. In addition, the builds include a slew of excellent original Resurrection Remix ROM add-ons. offers the greatest performance, customization, power, and the most up-to-date features for your smartphone!
6. MIUI 8:
MIUI 8 is the customized version of Android developed by XIAOMI, a Chinese smartphone manufacturer. The OS is open-source and can be modified easily with tons of customization options. The MIUI 8 supports features such as Dual Apps, Scrolling screenshot, second space, new gallery features, quick ball, calculator, Caller id, messaging features, and much more. This OS can be a perfect Custom OS for your Samsung Galaxy S21 Ultra.
7. Mokee OS
The Android Open Source Project provides the foundation for MoKee (AOSP). It includes extra localized and customized features while keeping to Material Design principles to keep the stock Android appearance.
Unlike OEMs, who release updates slowly and seldom, MoKee OS closely follows Google to deliver the most recent upgrades to our consumers, even extending support to devices that OEMs have declared outdated.
The source code for the ROMs is open source, secure, reliable, and excellent. It gives a wonderful experience by being buttery smooth and convenient.
8. XOSP OS
XOSP is an after-market firmware for a variety of Android phones based on CodeAuroraSources (CAF). The Xperia Open Source Project was started by @nilac for the Galaxy S+ (his old smartphone) years ago when the ROM was called S+ Reborn. The goal of XOSP OS was to develop a bloat-free ROM with Sony Xperia-specific applications and the usual modifications that customers expect from a custom ROM. S+ Reborn was a hit, and it was ultimately transferred to a variety of devices, thus it was renamed XOSP.
9. Havoc OS:
Havoc OS is a new Custom ROM based on Lineage OS that adds a slew of new features that aren’t seen in other Custom ROMs. The ROM has a System-wide Rounded UI, Spectrum compatibility, Battery Teak features, Status bar changes, OmniSwitch and Slim recent options for fast multitasking, and many more features.
10. Pixel Experience OS
The Pixel Experience OS includes all of the functions and programs that come standard with the Google Pixel smartphone. With this Custom ROM, you can now enjoy the true Pixel Smartphone.
I hope this guide has helped you to install a new Custom ROM on your Samsung Galaxy S21 Ultra. If you have any queries, feel free to comment down below.
11. Liquid Remix OS
It’s an Android 11 ROM with a plethora of manual UI modification possibilities. It also has Face and Fingerprint unlocking capabilities. It comes with camera2 API and Google camera app activated by default, both of which are not operating properly in Stock Rom. Another benefit of this ROM is that it allows OTA updates. There are several gestures to pick from, including the AOSP gesture, the Carbon gesture, and the stock gesture. You can easily install this custom ROM on your Samsung Galaxy S21 Ultra.
12. Evolution X Custom ROM
Evolution X is a flashable Custom ROM to bring a true Pixel experience to your Android Device, with many additional configurations at your disposal. The platform provides many security patches and updates regularly. Although The ROM is based on Android 11 you must try Lineage OS first.
13. Candy OS
The Candy OS can be a very sweet OS for your smartphone, it gives greater performance than other ROMs available. The operating system is based on Android 12, so if you want to experience Android 12 on your Samsung Galaxy S21 Ultra then go for it.
We have tested this method on our Samsung Galaxy S21 Ultraand the same is listed below but remember, Infofuge.com is not responsible for any damages caused on your phone by following this guide. Try these methods with your own risk!
How To Install A Custom ROM on Samsung Galaxy S21 Ultra?
To install a custom ROM on your Samsung Galaxy S21 Ultra there are some things that you need to keep in mind are listed below:
- First, make sure that you have unlocked the bootloader on your Samsung Galaxy S21 Ultra.
- Next, you need to have TWRP recovery installed on your Samsung Galaxy S21 Ultra. TWRP is the most essential part of installing any custom ROM on your phone, and without it, you cannot flash any custom ROM.
- Make sure your device is fully charged.
- Now you need to root your Samsung Galaxy S21 Ultra.
- Take a complete backup of your device, as flashing a new ROM will erase all the data inserted in your device.
Remember The Guide is only for the Samsung Galaxy S21 Ultra and you cannot try this guide on any other device. If you try this on any other model your device may get bricked.