A Deep Dive into Custom ROMs for the Samsung Galaxy A9 (2018): Breathing New Life into a Quad-Camera Pioneer Introduction: The Forgotten Mid-Ranger The Samsung Galaxy A9 (2018) was a bold experiment. As the world’s first smartphone with four rear cameras, it aimed to bring versatility to the mid-range segment. However, like many Samsung phones from this era, it shipped with the heavy, resource-hungry Samsung Experience UI (later One UI). Fast forward a few years, and the official software support has long ended, leaving users stuck on Android 10 (One UI 2.1) with outdated security patches. Enter the custom ROM community. For those willing to tinker, custom ROMs offer a lifeline. After spending two months flashing, testing, and daily driving several ROMs on my A9 (SM-A920F), here is my exhaustive review of the current landscape. Why Bother with a Custom ROM on the A9 2018? Before diving into specific builds, let’s address the elephant in the room: Is it worth it?
The Pros: Dramatically improved performance (the Snapdragon 660 feels snappier without Samsung’s laggy UI overlay), up-to-date security patches (Android 13/14 vs stock Android 10), vastly better RAM management, and a stock Android experience reminiscent of Pixels. The Cons: You lose Samsung-specific features (Secure Folder, Samsung Pass, Good Lock). The quad-camera setup is reduced to a basic single-lens functionality in most ROMs. Samsung Pay is gone. Also, there is always a risk of bricking if you are not careful.
The Main Contenders (Status: Early 2025) The A9 2018 is not as popular as the Galaxy S series, but a few dedicated developers on XDA and Telegram have kept it alive. The most stable and actively maintained ROMs are:
LineageOS 20 (Android 13) – The most stable daily driver. Project Elixir (Android 13/14) – For those who want customization. crDroid (Android 13) – Feature-packed but slightly heavier. Pixel Experience / PixelOS (Android 13) – For the pure Google experience. custom rom for samsung a9 2018
Detailed Review: LineageOS 20 – The Gold Standard I spent three weeks on LineageOS 20 (Unofficial, maintained by a developer named Aarav on Telegram). Installation Experience: Moderate difficulty. You need to unlock the bootloader (which wipes data and trips Knox—but on an old phone, who cares?), install a custom recovery (TWRP), and then flash the ROM. The instructions are clear, but newbies might struggle with the vendor partition requirements. Warning: The A9 has a fragile bootloader unlock process; you must enable OEM unlocking in dev settings and wait for the 7-day timer if you just reset the phone. Performance & Daily Use: 9/10 Wow. The difference is night and day. Stock One UI 2.1 feels like wading through molasses. LineageOS 20 is fluid. Apps open faster, the app drawer doesn’t stutter, and the 6GB of RAM finally feels like 6GB. UI transitions are smooth at 60Hz (the screen is only 60Hz anyway). Gaming (Call of Duty Mobile on medium settings) is actually more stable because the CPU isn’t throttling under Samsung’s thermal profile. Battery Life: 8/10 With the original 3800mAh battery (now several years old), I averaged 5.5 to 6 hours of screen-on time. That’s about 30 minutes more than stock. Idle drain is excellent—losing only 2-3% overnight. Adaptive battery works better here than on stock. The Quad-Camera Situation: 5/10 Here is the biggest compromise. Stock Samsung camera software is proprietary. On any AOSP-based ROM, the four cameras (Telephoto, Ultra-wide, Depth, Main) are reduced to just the main 24MP shooter . You cannot switch to the 2x optical zoom or the ultra-wide lens. The Google Camera (GCam) port (specifically for SDM660) helps—it takes better main camera photos than stock thanks to HDR+—but you lose hardware-level switching. If you rely on those extra lenses, do not flash a custom ROM. Connectivity & Bugs:
Wi-Fi/Bluetooth: Perfect. No drops. NFC: Works for Google Pay (if you hide root with Magisk). Audio: Works fine, but the dual speaker mod (using earpiece as second speaker) from stock is gone. Known bug: Auto-brightness is a little slow to react. Also, VoLTE works on some carriers but not all; check your region.
Project Elixir – The Customization King After Lineage, I tried Project Elixir. It’s based on AOSP but with tons of customizations—status bar icons, lock screen clocks, monet theming, and a built-in launcher that feels like OneUI’s app drawer mixed with Pixel. Performance: Slightly heavier than LineageOS. You’ll notice a micro-stutter when pulling down the notification shade 10% of the time. Battery life is 30 minutes less. Why choose this over Lineage? If you miss Samsung’s “Good Lock” style customization, this is your answer. The amount of UI tweaks is staggering. However, stability takes a minor hit. PixelOS – For the Purist This one aims to replicate the Pixel experience exactly. It comes with Google apps pre-included, Pixel launcher, and even the “At a Glance” widget. The good: It feels like a Google phone. The camera (using GCam) integrates nicely. The call screening feature (on supported regions) works. The bad: The ROM maintainer for A9 lost interest, so the last update was 7 months ago (Android 13 QPR3). Security patch is outdated. I wouldn’t use this for banking. The Major Dealbreakers You Must Know A Deep Dive into Custom ROMs for the
Camera is crippled. If you use ultra-wide or telephoto daily, stick with stock Android 10. Samsung Good Lock / Secure Folder is gone. No way around it. No Android 14 (stable) yet. While some devices get A14, the A9’s A14 builds are experimental with broken RIL (mobile data). Stick to Android 13. SafetyNet / Play Integrity: Out of the box, most ROMs fail Google’s Play Integrity checks. You must root with Magisk and install a module like “Play Integrity Fix” to use Google Pay or banking apps. This adds maintenance overhead.
Who is this custom ROM for?
The Tinkerer: You enjoy the process of flashing and optimizing. The Privacy-Conscious User: You want to de-Google or run Graphene-like features (though note: no official Graphene for A9). The Performance Seeker: You hate how slow One UI has become and just want a snappy device for social media, browsing, and light gaming. Someone with a dead motherboard: If you brick your A9, you aren’t losing a $1000 phone. Fast forward a few years, and the official
Who should absolutely avoid this?
Camera enthusiasts (you bought the A9 for its quad lenses). Samsung ecosystem users (Galaxy Buds features, Galaxy Watch integration). Someone who needs “it just works” with no tinkering.