Last Updated on December 12, 2022 by Mathew Diekhake

A smartphone like the Redmi Note 9S can last for a lot of years. But, the software on it is only supported for two to three years before updates stop arriving. You shouldn’t have any problem using the same software for several more years, and it may even make more sense to keep aging hardware on older software otherwise the hardware may not be able to cope with the new features coming out in the software. That said, if you are an Android enthusiast, it’s not much fun to sit around knowing that newer software versions are available and yet they’re not arriving on your device. This is one of the reasons people install custom ROMs.

A custom ROM can help you update the Redmi Note 9S to newer versions of Android. However, you can also downgrade your software which may even be more important to do sometimes. If you think you notice a bug, you generally can’t downgrade the Android operating system to that older version you were using before. But you can downgrade by installing a custom ROM based on that older firmware version. There are various reasons to install custom ROMs — it doesn’t have to be updating and downgrading — but they are two of the more common reasons.

Caution:
These custom ROMs are only for the Indian variant of the Redmi Note 9S.

Notes:

  • To install custom firmware on the Redmi Note 9S smartphone, you need to have unlocked the bootloader and installed a custom recovery image. Here is the XDA thread that offers TWRP recovery for the Redmi Note 9S. There is also an OrangeFox recovery.
  • There are lots of custom ROMs for the Redmi Note 9S. We’ve tried to show the best custom ROMs, but more may come in at any time. This list is not a guarantee that there are no other good ROMs out there. Please leave comments regarding any we have missed!
  • Youssif Shaaban Alsager has developed a Xiaomi firmware updater tool that installs stock firmware. If the only reason you are installing custom firmware is to get newer firmware, you may be interested in trying that instead. We can see this tool gets lots of downloads and the developer has his own GitHub page with hundreds of followers.

Project Elixir

The Project Elixir custom ROM is an official ROM. It is based on AOSP and Android 13. The purpose of this ROM is for it to give a close-to-stock Android experience. It’s quite a popular ROM as you can see from the number of comments on its XDA thread. You can also check the download link for screenshots that have been provided by the ROM developers.

Download: Project Elixir

LineageOS 18.1

This is an official LineageOS 18.1 custom ROM. This is by far the most popular custom firmware to install on the Redmi Note 9S. LineageOS 18.1 is based on Android 11. Before LineageOS 18.1, there was an unofficial LineageOS 17.1 that proved to be very popular.

Download: LineageOS 18.1

PixelPlusUI

PixelPlusUI is an official custom ROM based on Android 13. PixelPlusUI is custom firmware designed to mimic the Google Pixel. PixelPlusUI has its own website you can check out. PixelPlusUI is available for many devices and is one of the most installed custom ROMs. I like this ROM a lot and would not hesitate to install it. It even has developer support in case you run into any issues.

Download: PixelPlusUI

PixelOS

The PixelOS custom firmware is also based on the software you get on the Google Pixel smartphones. This PixelOS ROM is based on Android 12.1 and it’s an official and stable build. It’s based on AOSP. One user has complained of there being too much battery drain. But apart from that, it looks pretty good. I thought more people would have installed it though. Perhaps they are more interested in Android 13 now.

Download: PixelOS

PixelExperience

There is also a PixelExperience custom ROM based on AOSP. This is the least popular of the three today because it’s only based on Android 11. There’s nothing wrong with Android 11 though. My current model Moto G Power is running official Android 11 today.

Download: PixelExperience

CrDroid 9.0

CrDroid 9.0 is an official custom ROM but it’s also still in its beta stages. There’s also another CrDroid v8.1 is you prefer it.

Download: CrDroid 9.0

RavenOS

I’m not sure but I think this RavenOS is purely custom firmware for Android and not related to the other RavenOS which has been made for crypto miners. I won’t link to the crypto mining site but it owns the main RavenOS domain. I can see by the comments on XDA that this RavenOS custom firmware has only been available since about March of 2022 so it’s a new ROM in general. One user mentioned an error after installing it. They couldn’t update the vendor when using the OrangeFox recovery. Apart from that, there are very few comments so far.

Download: RavenOS

NusantaraProject

The NusantaraProject custom firmware is based on Android 12 and has been available since roughly September of 2021, so it’s a bit older than many of the others. One user claims it is the best ROM they have ever tested. You can also skvalex from Magisk repo to get call recording on this ROM according to another user.

Download: NusantaraProject

Evolution X

Evolution X was once an extremely popular custom ROM to install on the Redmi Note 9S. Undoubtedly there are still many people using it, but it’s only based on Android 10, which is now considered outdated.

Download: Evolution X

Several unofficial custom ROMs aren’t as popular. You have the Havoc OS v4.14 based on Android 11. There is also the Project Streak v12.1 based on Android 12.1. PixysOS v5.1.1 is also based on Android 12. There was also an unofficial LineageOS 18.1.

As you can see, there is no shortage of custom firmware for the Redmi Note 9S smartphone. If you were to browse the XDA forum yourself, you could probably find some more. Please leave comments if we have accidentally left out any of the obvious main ones worth mentioning.