Disclaimer: Installing custom ROMs can void your warranty, risk data loss, or brick your device if done incorrectly. Back up all data and ensure you understand the steps before proceeding.
Since official support for the Vivo Y71 ended at Android 8.1 Oreo, custom ROMs are the only way to experience newer Android versions. vivo Y71 - Full phone specifications - GSMArena.com vivo 1801 custom rom full
Additional Resources
Elian stared at the screen of his vivo 1801, officially known as the Y91i. It was a budget phone from a bygone era, running Android 8.1 (Oreo) with a skin called Funtouch OS that felt less like "fun" and more like a poorly translated fever dream. The bloatware was suffocating. The "Game Mode" popped up at random intervals. The storage was full, not because of photos, but because the system updates created a dumpster fire of cached data in the background. Deep Dive: Custom ROMs for the vivo 1801
The pursuit of a “Vivo 1801 custom ROM full” is not without peril. Hard-bricking is possible if the wrong bootloader or firmware is flashed, requiring EDL deep-flash and a shorting of test points on the motherboard. Warranty is void (though moot for a 2018 device). SafetyNet/Play Integrity fails by default, breaking Google Pay and some banking apps, though Magisk with Zygisk can hide modifications. Furthermore, the community is fragmented – many XDA threads for the Vivo 1801 are abandoned, and Telegram groups often share unverified builds containing malware or bloatware. LineageOS: The LineageOS build for the Vivo 1801