Just tried out a simple Java Swing popup and it uses 6Mb of heap so that's allright then ;). (on my machine it will reserve 160Mb of memory for thread stacks, code caches, buffers and GC but that won't be a problem unless you use it) In the 90s I also thought that was wasteful (my first PC had 32Mb). Nowadays with Electron apps taking up gigabytes it doesn't seem that bad anymore.