How do you allocate more ram to minecraft?

if you play modpacks through curseforge or modrinth, they ignore the vanilla launcher setting - each has its own memory slider in its settings. change it there or the pack keeps launching with the default.

java only - bedrock handles its own memory and there's no setting to change. in the launcher it's installations, edit the one you actually play, more options, then the -Xmx number in the jvm arguments. four gigs covers vanilla and a light modlist comfortably. the mistake is handing it most of the machine: it gets slower rather than faster, because there's more for it to sweep up each time. big modpacks normally state what they want, so use that number if there is one.