Default Launcher

  1. Open the Launcher and move to the “Installations” Tab
  2. Click the 3 dots on your profile and click “Edit”
  3. Click “More Options”
  4. In “JVM Arguments” look for “Xmx2G”, change that to “Xmx4G” for 4GB of RAM, “Xmx8G” for 8GB of RAM, etc
  5. Move back to the “Play” Tab and click “Play” to play the game.

Curseforge

  1. On the bottom-left of your curseforge window click the “Settings” Icon
  2. Go to the Minecraft settings
  3. Scroll to find “Java Settings” change the “Allocated Memory” slider to your desired amount
  4. Click close and you should be able to play