How to Allocate More RAM to Minecraft

Published: July 3, 2026 · 4 min read

One of the most common causes of Minecraft crashes, especially when running mods, is the game running out of allocated memory. By default, the official Minecraft Launcher only gives the game 2 GB of RAM. When you load a modpack with dozens of mods, 2 GB is nowhere near enough. Here is how to increase it correctly without causing new problems.

How Much RAM Should You Allocate?

The answer depends on how many mods you are running:

  • Vanilla or a few small mods: 2–3 GB is enough.
  • Medium modpack (20–60 mods): 4–6 GB is recommended.
  • Large modpack (100+ mods like All the Mods or RLCraft): 6–10 GB depending on world complexity.

Important: Do not allocate more than 50–60% of your total system RAM. If your PC has 16 GB, never go above 10 GB for Minecraft. Giving the game too much RAM can actually cause stuttering, because Java's garbage collector struggles to manage very large memory heaps and may pause the game for several seconds at a time to clean up.

Steps in the Official Minecraft Launcher

  1. Open the official Minecraft Launcher.
  2. Click on "Installations" at the top of the window.
  3. Hover over the profile you want to modify (e.g., "Fabric Loader 1.21") and click the three-dots icon, then "Edit".
  4. Click "More Options" to expand the advanced settings.
  5. Find the "JVM Arguments" field. You will see text like: -Xmx2G. Change the number to your desired value — for example, -Xmx6G for 6 GB.
  6. Click "Save" and launch the game.

Steps in CurseForge App or ATLauncher

Third-party launchers typically have a global Java settings page. In the CurseForge app, go to Settings → Minecraft → Java Settings and drag the memory slider to your desired amount. ATLauncher has a similar slider under Settings → Java/Minecraft. Modpack-specific memory overrides are available by right-clicking an installed pack and selecting "Edit."

Confirming the Change Worked

After launching the game, press F3 to open the debug screen. In the top right corner, look for a line that reads something like Mem: 45% 2048M / 6144M. The second number is your maximum allocated RAM — confirm it matches what you set. If Minecraft crashes before you can check, review the crash report file in your .minecraft folder for an OutOfMemoryError, which confirms you still need more RAM allocated.

← Back to Guides Hub