If you’re using a Samsung Galaxy S21 5G and want to breathe new life into your device, installing an Android 16-based custom ROM is a solid move. Google...
Mohammed Huwais
Last updated on June 18, 2026
Mohammed Huwais
Author
I started my career as a blogger in 2014 and also worked on an Android niche platform to gain extra income. I cover the topic on How to guides, software updates, Custom ROM updates and also product review. I'm 24 years old, completed MBA (Master of Business Administration) from Sikkim Manipal University.
If you’re using a Samsung Galaxy S21 5G and want to breathe new life into your device, installing an Android 16-based custom ROM is a solid move. Google recently released Android 16 for Pixel devices, and developers have already ported unofficial AOSP builds to older phones like the Galaxy S21 5G. In this guide, you’ll learn how to safely install Android 16 on Galaxy S21 5G and enjoy its latest features.
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The Samsung Galaxy S21 features a 6.2-inch Dynamic AMOLED panel with a 120Hz refresh rate. The screen can go all the way up to 1300 nits under extreme sunlight conditions. It has a resolution of 1080 x 2400 pixels and an aspect ratio of 20:9 ratio. With the Samsung S20, we get the Exynos 2100 chip built on a 5nm manufacturing process. It is an octa-core processor with one Cortex-X1 core clocked at 2.9 GHz, three Cortex-A78 cores clocked at 2.8 GHz, and four Cortex-A55 cores clocked at 2.2 GHz.
In terms of optics, we get a rear quad-camera setup consisting of a 12MP primary sensor paired with an f/1.8 lens, a 12MP ultrawide sensor paired with an f/2.2 lens, and a 64MP telephoto sensor paired with an f/2.0 lens. Coming to the front, we get a single 10 MP sensor paired with an f/2.2 lens. The rear setup can capture 8K videos while the front setup is only limited to 4K video recording.
We get a number of options when it comes to storage variants with 128GB, 256GB, and 512GB of internal storage, with 12 GB of RAM for the lower two variants and 16GB of RAM for the top variant. The phone comes with Android 11 out of the box with OneUI skinned on top of it.
.For connectivity, we get Wi-Fi 802.11 a/b/g/n/ac/6, Bluetooth 5.0, GPS, NFC, USB Type-C 3.2, and FM radio. And for the sensors, we get an ultrasonic under-display fingerprint sensor, accelerometer, gyro, proximity, compass, and barometer. In terms of battery, we get a 4,000 mAh cell that supports 25 fast charging. The S21 is available in four color options: Phantom Gray, Phantom White, Phantom Violet, Phantom Pink.
Android 16 introduces Material 3 Expressive, a refined evolution of Google’s design language for smartphones and tablets. While it doesn’t completely reinvent the interface, it represents one of the most noticeable user-facing changes in the OS. Rather than a dramatic visual overhaul, Material 3 Expressive enhances the foundation laid by Material Design 3 by introducing smoother, more dynamic animations, larger touch targets, and bolder typography.
This update arrives at a perfect moment. Material Design 3, first introduced with Android 13, had begun to feel dated. Material 3 Expressive breathes new life into the interface while preserving the familiar look and feel users have grown comfortable with. Instead of overhyping the changes, Google’s own animations showcase the polish and fluidity of this next step in Android design.
Android 16 introduces a wealth of new features, system optimizations, and UI refinements. Some of the highlights include:
These updates aim to improve user experience across different types of devices, including foldables, tablets, and standard phones.
Although Android 16 is rolling out first to Pixel devices, many brands like Xiaomi, OnePlus, Samsung, Realme, and others will follow soon. If you’re impatient, a custom ROM is the best way to get Android 16 today.
Everything seems to be working fine.
If you spot any bugs, report them along with proper logs to the developer.
Always back up your device before flashing any ROM. This prevents data loss if anything goes wrong. Backup guide here.
Charge your phone to at least 50% to avoid shutdowns during the flashing process.
You can skip this part if you have already installed TWRP Recovery on your Galaxy S21 5G. For those who haven’t, ADB and Fastboot commands (platform-tools) are required to boot your device into bootloader mode, allowing you to perform the necessary flashing operations. ADB (Android Debug Bridge) establishes a connection between your device and computer, while Fastboot is a more advanced command-line utility for flashing and modifying Android devices.
You can download the ADB and Fastboot Binaries (Platform-Tools) here.
You’ll need the appropriate USB drivers to ensure a successful connection between your Galaxy S21 5G and your computer. These drivers enable file transfers, flashing, and other operations between your devices.
You can download the latest Samsung USB drivers here.
Unlocking the bootloader of your Galaxy S21 5G. is essential before you can install any custom ROM. Make sure to follow Samsung’s official instructions for unlocking the bootloader. Unlocking the bootloader will wipe your device, so back up your data beforehand.
You must install TWRP Recovery on your phone to install any custom ROM on your device. After unlocking the bootloader, follow our guide to install TWRP Recovery on your Galaxy S21 5G.
You can download the Android 16 custom ROMs for the Samsung Galaxy S21 5G from the links below:
| OS | Download Link |
| Lineage OS 23 | Download |
Most AOSP ROMs don’t come with Google apps. You’ll need to flash Android 16 GApps separately.
Note: Flash GApps right after flashing the ROM. Don’t reboot in between.
Warning!
GetDroidTips is not responsible for any issues that may happen to your device if you flash it on another device and brick it. Do it at your own risk.
adb reboot recovery
The first boot after installing a custom ROM may take a bit longer than usual, so don’t panic if it seems slow. After the device boots, you will need to set it up as a new device, just like when you first got it.
By flashing Android 16 on your Galaxy S21 5G, you’re extending its life and unlocking modern Android features that Samsung may never officially provide. While this is an unofficial AOSP build, early reports suggest solid stability. That said, bugs may still appear, so always report them with logs to help developers improve the experience.
If you have questions or run into issues during installation, feel free to drop a comment. Enjoy your fresh Android 16 experience!
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