This is a gray area. The tool itself is a reverse-engineered version of proprietary Qualcomm software. Distributing it violates Qualcomm's EULA. However, using it on a device you own is generally considered legal in most countries for the purpose of repair under "right to repair" laws. Using it to unlock paid subscriptions, remove carrier locks, or bypass rental protections is illegal.
Xiaomi, Oppo, and Vivo devices often have locked bootloaders preventing cross-region flashes. QFL v10 Full bypasses the bootloader lock entirely, allowing a full flash of a different region’s firmware. qfl qualcomm flash loader v10 full
: QFIL does not require formal installation; it can be run directly after extracting its zip file. This is a gray area
: QFIL is usually included in the QPST installation package. remove carrier locks