“Reflector is a Python script which can retrieve the latest mirror list from the Arch Linux Mirror Status page, filter the most up-to-date mirrors, sort them by speed and overwrite the file /etc/pacman.d/mirrorlist.”

In my case I use the command:

reflector --country Germany,Austria --age 12 --protocol https --sort rate --save /etc/pacman.d/mirrorlist

https://wiki.archlinux.org/title/reflector

https://man.archlinux.org/man/reflector.1