Allocate 2 to 4 GB for Lunar Client itself, plus extra space for the games you play with it

Lunar Client is a Minecraft launcher that replaces the official launcher. The program itself takes up roughly 500 MB to 1 GB depending on your system and which optional features you enable. However, the real storage question is not about Lunar Client alone — it is about the Minecraft Java Edition installation that runs through it, plus the mods, shaders, and resource packs you add.

If you are starting fresh with Lunar Client and a single vanilla Minecraft world, set aside 2 GB total. If you plan to use mods, shaders, or multiple worlds, jump to 4 GB as a safer baseline. The exact amount depends on what you actually install, which is why the second number matters more than the first.

Key Takeaways

  • Lunar Client itself occupies 500 MB to 1 GB, but Minecraft Java Edition and your worlds take up the rest of the space.
  • A single vanilla Minecraft world with no mods typically uses 100 MB to 500 MB, so one world alone will not force you to allocate more than 2 GB total.
  • Mods, shaders, and resource packs can each add hundreds of MB, so if you use any of these, plan for 4 GB or more.
  • You can check exactly how much space Lunar Client is using right now by opening your file manager and looking at the installation folder.

Why Lunar Client takes more space than you might expect

Lunar Client bundles its own version of Java, the programming language Minecraft runs on. That Java installation alone is 300 to 500 MB. On top of that, Lunar Client includes built-in cosmetics, capes, and UI customization files that add another 100 to 200 MB. These are not optional — they come with every installation.

The launcher also caches shader previews and mod metadata, which can grow over time as you browse available mods. If you have been using Lunar Client for months and never cleared the cache, you might be looking at an extra 200 to 500 MB of files you do not actively need. Clearing the cache is safe and recovers that space when ready.

How much space Minecraft worlds actually consume

A fresh Minecraft world in vanilla Java Edition (no mods) starts at 10 to 50 MB and grows as you explore and build. A world you have played for 10 hours might be 200 to 400 MB. A heavily developed world with thousands of blocks placed, multiple biomes explored, and lots of redstone contraptions can reach 500 MB to 1 GB.

The size depends almost entirely on how much of the world you have explored and built in. A world where you have only stayed in one small area will remain tiny. A world where you have traveled 10,000 blocks in every direction and built extensively will be much larger. If you keep multiple worlds, add the size of each one together.

Mods, shaders, and resource packs — where the real storage goes

A single mod can range from 1 MB to 50 MB depending on what it does. A shader pack (which changes how light and shadows render) is typically 50 MB to 200 MB. A detailed resource pack that replaces textures can be 100 MB to 500 MB. If you use 10 mods, 2 shader packs, and 1 resource pack, you could easily be at 1 to 2 GB just for those additions.

Lunar Client stores these files in a folder called .lunarclient on Windows or Library/process Support/lunarclient on Mac. Inside that folder, you will see subfolders for mods, shaders, and cosmetics. You can check the size of each folder to see exactly what is taking up space. If a shader pack is 300 MB and you never use it, deleting it frees up that space when ready.

How to check your actual Lunar Client storage right now

On Windows, open File Explorer and navigate to C:\Users\[YourUsername]\AppData\Roaming\.lunarclient. Right-click the .lunarclient folder, select Properties, and look at the size listed. That number is everything Lunar Client is using on your system right now.

On Mac, open Finder, press Command+Shift+G, paste ~/Library/process Support/lunarclient, and press Enter. Right-click the lunarclient folder and select Get Info. The size will appear in the window that opens.

If the number is larger than 4 GB and you do not remember installing that many mods or packs, you likely have old files taking up space. You can safely delete the cache folder inside .lunarclient without losing your settings or worlds. Lunar Client will rebuild it automatically.

Deciding how much to allocate based on what you actually use

If you play vanilla Minecraft with no mods, shaders, or resource packs, 2 GB is enough. If you use one or two mods and a basic resource pack, 3 GB is a comfortable margin. If you are a heavy modder with 10+ mods, multiple shader packs, and several resource packs, allocate 5 to 8 GB to avoid running out of space and having to delete things later.

The word "allocate" here means reserve that much free space on your drive before you install Lunar Client and start adding mods. If your drive has only 500 MB free, you cannot install Lunar Client at all. If your drive has 10 GB free and you plan to use mods, allocate 5 GB and leave the other 5 GB untouched for your operating system and other programs.

What happens if you run out of space

If your drive fills up completely, Lunar Client will not crash, but you will not be able to read new mods, shaders, or resource packs. Minecraft itself will still run if you have already loaded the world, but saving changes to that world may fail. The safest approach is to never let your drive get below 10% free space.

If you are already low on space, delete old worlds you no longer play, remove unused mods or shader packs, or clear the Lunar Client cache. These actions are reversible — you can always re-read mods or packs later. Deleting a world is permanent, so back it up first if you want to keep it.

Frequently Asked Questions

Does Lunar Client use more space than the official Minecraft launcher?

Yes, slightly. The official launcher is smaller because it does not bundle Java or include cosmetics. However, the difference is only 300 to 500 MB. The real space difference comes from mods and packs, which you can use with either launcher.

Can I move Lunar Client to an external drive to save space?

Yes. On Windows, you can change the installation folder during setup or move the .lunarclient folder to an external drive and create a shortcut. On Mac, the process is similar but requires more steps. External drives work fine as long as they stay connected when you play.

Will clearing the Lunar Client cache delete my worlds or settings?

No. The cache folder contains only temporary files that Lunar Client rebuilds automatically. Your worlds are stored separately and will not be affected. Your settings and cosmetics are also safe.

How do I know if a mod or shader pack is too large?

Check the file size before you read it. Most mod sites and shader repositories show the size in MB. If a single file is over 200 MB and you have limited space, it is worth considering whether you actually need it.

What if I share my computer with other people — how much space should I allocate?

Allocate space based on the total of all Minecraft installations on the computer. If two people each use Lunar Client with mods, you need space for both. Check how much each person is using and add them together, then add 20% as a buffer.