The Redmi 1S launched in 2014 on Android 4.4 KitKat under Xiaomi’s MIUI skin, and custom ROMs for it are a relic of the early-2010s Android modding scene rather than an active project today. This isn’t a shoppable product — custom ROMs are free community-built firmware installed via a recovery tool — so this is a guide to what actually existed for the device and the state it’s in now, not a list to buy from.
What was actually released for the Redmi 1S
- CyanogenMod 12 / 12.1 (Android 5.0/5.1 Lollipop) — Built by XDA developer Syhost, this was the most popular unofficial CM12 build for the device, bringing stock-Android-style Lollipop to a phone that shipped on KitKat.
- LineageOS (unofficial builds) — As CyanogenMod wound down in 2016, some of its Redmi 1S work carried over into early unofficial LineageOS builds, though official Lineage support for a device this old was never guaranteed and dried up as the maintainer community moved to newer hardware.
- Mokee OS 5.1.1 — Also released by Syhost for the Redmi 1S, Mokee was a CyanogenMod-based ROM with its own theming layer, popular in the same XDA thread as the CM12 builds.
- Stock MIUI (later versions) — Not a “custom” ROM, but worth naming: Xiaomi’s own MIUI updates for the 1S stopped years ago, which is exactly why the custom-ROM threads existed in the first place — people wanted a newer Android version than Xiaomi kept shipping.
Why this list is short, and what that means for you today
Unlike a current flagship with an active XDA thread, the Redmi 1S’s custom-ROM scene was built almost entirely by one or two individual developers (Syhost being the name that recurs across every build listed above), working on 2014-era hardware with a 1GB RAM ceiling that later Android versions strain against. XDA’s own forum activity for “redmi 1s” has gone quiet, and none of these builds have been meaningfully updated in years — there is no actively maintained 2026 custom ROM for this device. If you’re using a Redmi 1S today, the realistic options are: stay on the last MIUI update it received, flash one of the CM12/Mokee builds above as-is (accepting no future security patches), or treat the device as a secondary/offline unit rather than a daily driver.
Before you flash anything
Installing a custom ROM requires an unlocked bootloader and a custom recovery (TWRP was the standard tool for this device), and it will wipe your data and void any remaining warranty. Because none of the Redmi 1S builds are actively maintained, back up everything first and don’t expect further updates or bug fixes after installation — you’re installing a snapshot from an inactive project, not a supported ROM.