Despite its simple graphics, Minecraft can be an absolute resource hog. With a higher render distance or a large number of entities on the screen at once, Minecraft may use a very large amount of RAM. The default RAM allocation for Minecraft works well on most computers but can be too small for players using high-end computers with high requirements.
This guide only concerns Minecraft: Java Edition, not the Bedrock Edition that runs on consoles and mobile devices.
Determine How Much RAM You Have
Before you can figure out an appropriate amount of RAM to allocate to Minecraft, you need to know how much RAM your computer has in the first place. On a Windows 10 PC, open Settings from the Start menu. Navigate to System > About, then scroll down to Device Properties. You’ll see how much RAM you have in the Installed RAM section, as visible in this screenshot:
On a Mac, click the Apple logo in the menu bar, then open About This Mac. Navigate over to the Memory tab like in the image below:
Now that you have figured out exactly how much RAM you have in your computer, you can determine an appropriate amount of RAM to allocate to Minecraft. 2GB is the default; anywhere between 2GB and half of your computer’s installed RAM is a sensible amount to allocate to Minecraft.
Changing JVM Arguments in the Minecraft Launcher
Since it is a program written on the Java platform, Minecraft can be allocated more RAM by adjusting the Java Virtual Machine (JVM) settings. The official Minecraft launcher makes adjusting these settings simple. While the following screenshots are all taken on a Mac, the process is identical on Windows PCs as well.
Start by opening the Minecraft launcher. You should see a window similar to this one:
Next, click on the Installations tab. Mouse over the Minecraft installation you want to use, then click the ellipsis button and choose Edit.
Click More Options and scroll down to the JVM Arguments section.
The very first JVM argument (-Xmx2G in this example) represents the maximum amount of RAM allocated to Minecraft. Change the number 2 to a larger number and click Save. Anywhere between 2GB and about half of your computer’s RAM is a reasonable amount. Make sure to leave enough for other applications that you might be using while playing Minecraft.
What About Minecraft Servers?
If you’re running a small Minecraft server on your own computer, you can allocate more RAM to that server using JVM arguments, although you will need to edit them in a different way.
Locate the containing the Minecraft server executable. You can search for “Minecraft_Server” to make this easier. Once you find that folder, create a new text file in the same directory using Notepad on Windows or TextEdit on macOS. Paste the following text into the text editor and save it with a .bat or .sh extension (for Windows and macOS/Linux, respectively):
Windows: java -Xmx####M -Xms####M -exe Minecraft_Server.exe -o true
macOS and Linux: #!/bin/bash
java -Xms####M -Xmx####M -exe Minecraft_Server.exe -o true
Replace #### with the amount of RAM in MB that you want to allocate (examples include 2048 for 2GB and 5120 for 5GB). If the name of your Minecraft server executable is not Minecraft_Server.exe, replace that section with the actual name of the executable. Now, instead of running the Minecraft server executable directly, just type the name of your script.
Whether you’re just playing normally or hosting a server on your computer, changing the amount of RAM dedicated to Minecraft can make your gameplay experience much smoother.