JOSEUISLEY BTW, in order to install LineageOS 18.1 on the device you have to unlock the bootloader (which is a relatively annoying process for this phone, since you have to get an unlock request approved). I unlocked my Xiaomi Redmi 3 bootloader all the way back in December 2016 so I can't speak for if it still works in 2024. YMMV
(If you can somehow find one that already has any custom ROM on it, that would make things a lot easier, but I'm not sure how common that is)
The "Part 1" section of the answer to this post is pretty much what I remember doing (note that 3S and 3 are different phones, but the bootloader unlock process is very similar between them):
https://android.stackexchange.com/questions/177695/how-to-unlock-bootloader-root-and-install-twrp-on-redmi-3s-should-work-with
Note that:
- it's been way too long to remember what the factory stock ROM (MIUI 7 Android 5) felt like for me. I don't remember having any major issues but there's also a chance that it's not good
- every single other Android 5/6/7/8 custom ROM that wasn't 18.1 caused really annoying eyestrain
- specifically the LineageOS 18.1 (Android 11) ROM with HW overlays disabled is the only custom ROM I've found that doesn't cause the strain at all!
LineageOS 18.1 is the only ROM I can "100% confirm" from experience is strain-free
This is the ROM I used:
https://xdaforums.com/t/index-redmi-3-custom-roms-kernels-etc-19-02-2021.4099085/post-83830503
Also note that depending on where you live it's either possible or NOT possible to use it as a real "phone" with cell service in 2024 — in the USA, I was able to get a 3G signal on T-Mobile back in 2016-2018, but today, it only can be used as a "WiFi-only tablet" in the USA because of the 3G shutdown
If a carrier in your country supports the phone's 4G bands (which was never the case in the USA, even back then, but is more likely to be true in many other countries) there's a chance you can still get 4G signal on it though 🙂
If you're only planning to use it as a tablet (which is what I am doing) you don't have to worry about this cellular stuff