If Minecraft starts stuttering after you install a modpack or push render distance up, the fix most people search for first is giving the game more RAM. Allocation sets the maximum amount of memory Minecraft: Java Edition is allowed to use, and you change it with one line in the official launcher.
Bigger is not automatically better, though. Windows, Discord, your browser and any recording app all share the same pool of memory, and whatever you hand to Minecraft is no longer available to them.
This guide covers where the setting lives, how much to give on 4, 8, 16 and 32 GB machines, what happens when you give too much or too little, and how CurseForge, Prism Launcher and dedicated servers handle memory.
We rechecked Minecraft's help center, the Java Edition 26.1 changelog and launcher documentation on November 10, 2026, when the latest full release was Java Edition 26.3.
If the game keeps crashing after you change the value, memory may not be the real cause, so also work through our Minecraft crash and lag fixes, which go edition by edition.
The short answer: start at the 4 GB default, cap it at half your RAM
Java Edition 26.1, released in March 2026, raised the official launcher's default allocation from 2 GB to 4 GB.
Mojang said the bump was meant to make the game run smoother and reduce stutters, and the same version switched the garbage collector (the part of Java that cleans up unused memory) from G1GC to ZGC on compatible devices.
So for vanilla play without mods, leaving the default at 4 GB is the right starting point. Minecraft's help center gives three rules. On a PC with 4 GB of RAM or less, lower the allocation to 2 GB for stability.
With 8 GB or more, you can raise it. On a 64 bit operating system, half of your RAM is the recommended maximum, and on a 32 bit system 4 GB is the ceiling.
On a 16 GB PC that means anything up to 8 GB is in range; inside that range, follow the modpack author's recommendation or raise the value 1 GB at a time until the stutter goes away.
Mojang also noted that third party launchers may not pick up the 26.1 defaults, so if you play through CurseForge or Prism Launcher, check that launcher's own memory setting. Finally, all of this is about Java Edition. Bedrock Edition has no JVM arguments field, so there is nothing to allocate by hand.
How to allocate more RAM in the official Minecraft Launcher
- 1Check your installed RAM and that Windows is 64 bitIn Windows, open Start, Settings, System, About. Look at Installed RAM and System type. Those two numbers set your ceiling: half your RAM on a 64 bit system, 4 GB on a 32 bit one. If you also want your CPU and graphics card details, our guide on how to check your PC specs in Windows 11 shows where each one is. Minecraft's help center recommends backing up your worlds before changing settings, so do that now too.
- 2Open the installation you actually playLaunch the Minecraft Launcher, sign in with your Microsoft account and choose Minecraft: Java Edition on the left. Open the Installations tab at the top, pick the installation you want to change and edit it, then click More Options to expand the extra fields. Each installation stores its own value, so if you keep separate installations for the latest release and for mods, edit the one you launch.
- 3Copy the original JVM arguments to NotepadSelect everything in the JVM Arguments field, paste it into Notepad and save the file. If the game fails to start later, pasting this text back restores the original. The field holds other arguments besides memory, such as the garbage collector flags, all on one line, so be careful not to delete them or add line breaks.
- 4Change only the number after -XmxFind the part that starts with -Xmx. On a fresh 26.1 or later installation it reads -Xmx4G; an older installation may still say -Xmx2G. Change only the number. -Xmx6G means 6 GB, and -Xmx6144M is the same 6 GB written in megabytes. Use G or M as the unit and never write GB. The help center says that if the game will not launch afterwards, check for typos and upper or lower case mistakes first. When you are done, click Save.
- 5Play, then check how much memory is leftHit Play and play the way you normally do. With your recorder, Discord and browser open as usual, press Ctrl+Shift+Esc to open Task Manager and look at Memory on the Performance tab. If Available is close to zero, lower the allocation by 1 GB or close something. If there is plenty left and a modpack still stutters, raise it 1 GB at a time. If Minecraft will not start at all, paste your Notepad backup back in, or create a new installation of the same version and try that.
- 6Set CurseForge, other launchers and servers separatelyThe CurseForge app sets memory in two places: the Minecraft section of the app settings applies to every modpack, while a modpack's Profile Options apply to that pack only. Modpacks default to 4 GB (4096 MB), the app shows a warning if you go past 75% of system memory, and it can apply the modpack author's recommended value automatically. In Prism Launcher, use the Memory section of the Java settings. For a server you host, the start command sets memory with -Xmx (maximum) and -Xms (what it grabs at start), and the official server download page gives a command that begins java -Xmx4G -Xms4G. Since 26.1 the game needs Java 25. The official launcher bundles the Microsoft Build of OpenJDK 25, so there is nothing extra to install, and the CurseForge app installs Java for you as well. In a launcher where you pick Java yourself, such as Prism Launcher, or on a server, check that Java 25 is selected (the latest release as of November 10, 2026, 26.3, also uses Java 25).
How much RAM to allocate to Minecraft, by PC (as of November 10, 2026)
| Your PC and use | Java Edition allocation (-Xmx) | Why, and what to watch |
|---|---|---|
| 4 GB of RAM or less | 2 GB (-Xmx2G) | The help center says to drop to 2 GB for stability. The default has been 4 GB since 26.1, so you must lower it by hand or risk crashes. |
| 8 GB of RAM | 4 GB (keep the default) | Half your RAM, the recommended 64 bit maximum, is exactly 4 GB. If you record or run Discord alongside, do not go higher. |
| 16 GB, vanilla or light mods | 4 GB (default) | Mojang raised the default to 4 GB to cut stutter. Only add 1 GB at a time if you see signs of running out of memory. |
| 16 GB, large modpack | Pack's recommended value, up to 8 GB | CurseForge defaults modpacks to 4 GB and warns past 75% of system memory. The official recommended cap here is 8 GB. |
| 32 GB or more | Pack's recommended value (cap 16 GB) | More RAM is not more speed. Prism Launcher's docs say 4 GB is plenty for most play unless you run a big modpack. |
| Hosting a server on the same PC | 4 GB for the server plus your game allocation | The official server page's start command uses -Xmx4G -Xms4G. Keep server plus game low enough that Windows still has room. |
Checklist after changing the allocation
- I checked my installed RAM and that Windows is 64 bit
- I saved the original JVM arguments in Notepad
- I changed only the number after -Xmx and used G or M as the unit
- The allocation is no more than half my RAM (4 GB or less on 32 bit)
- With my recorder and Discord open, Task Manager still shows memory available
- If I use CurseForge, another launcher or a server, I set memory there too
Recording your Minecraft sessions
The easiest way to tell whether a new allocation actually reduced stutter is to watch the footage back. DOR is a free Windows app that detects Minecraft when you launch it and records the whole session from launch to exit, then collects the recordings in My Clips inside the app.
You can record the same walk through your base before and after changing the value and compare them, or pick out the moments worth keeping, like a finished build or an Ender Dragon kill, and trim them to 16:9, 9:16 or 1:1.
Game audio and your microphone go on one track, and on supported NVIDIA graphics cards such as the RTX series DOR records with NVENC hardware encoding. The free plan records at 1080p and 30 fps by default.
When long sessions fill the full gameplay recordings quota (5 GB by default), the oldest footage is cleared first, while your latest recording and anything you liked stay. To choose resolution and frame rate, see our Minecraft recording settings guide, and to send a trimmed moment to friends, see how to share Minecraft gameplay videos.
