Custom ROMs eliminate background bloatware, freeing up RAM and CPU cycles.

In this article, we will explore everything you need to know: the best custom ROMs available, step-by-step installation guides, risks, benefits, and post-installation tweaks.

Some modders hoped for a MediaTek (MTK) exploit. The Y1S uses the . Historically, MTK devices had SP Flash Tool vulnerabilities that allowed bootloader bypasses. However, Vivo pairs its MTK chips with proprietary preloader handshakes. By 2020, most known exploits were patched. Attempts using mtkclient (an open-source tool) on the Y1S generally fail or risk a hard brick.

: Perform a "Full Wipe" (Dalvik, Cache, System, and Data).

Navigate to the directory containing your downloaded Custom ROM file.

If you own a Vivo Y1S and want a custom ROM, your realistic options are:

Access newer Android features and security patches long after official manufacturer support has ended.

Maintain at least 60% battery life to prevent unexpected shutdowns.

| | Explanation | | :--- | :--- | | Hard Brick | If you flash the wrong preloader or a ROM for a different chipset, the phone may become unrecoverable. | | IMEI Loss | Some users report null IMEI (no cellular signal). Always backup your NVRAM partition before flashing. | | Camera Quality | Proprietary Vivo camera algorithms are lost. Expect washed-out photos. | | No VoLTE / VoWiFi | Most custom ROMs disable Voice over LTE on MediaTek devices. | | SafetyNet / Play Integrity | Banking apps and Netflix may stop working unless you use Magisk + Play Integrity Fix. |

Use SP Flash Tool to flash the recovery.img to the recovery partition. Step 3: Installing the GSI ROM