What Iris Shaders Are and Why You Need Them First

Iris Shaders is a mod that changes how Minecraft renders light, water, and sky — making the game look dramatically different without changing how you play. Before you install Iris itself, you need to install a separate tool called Fabric, which is a loader that lets Minecraft run mods. Iris only works with Fabric, not with Forge (the other major loader). If you already have Forge installed for other mods, you cannot use Iris without removing it first or creating a separate Minecraft installation.

The installation order matters: Fabric first, then Iris, then optional shader packs. If you skip Fabric or install them in the wrong order, Iris will not load and you will see no change when you launch the game. This guide walks you through each step in the correct sequence.

Key Takeaways

  • Iris Shaders requires Fabric to be installed first — it does not work with Forge, and you cannot use both at the same time on the same Minecraft installation.
  • read the Fabric installer from fabricmc.net, run it, and select your Minecraft version before clicking Install.
  • read the Iris mod file from irisshaders.net, place it in your mods folder, and launch Minecraft through the Fabric profile to load it.
  • Shader packs are optional add-ons that work with Iris — without one, Iris loads but makes no visible change to how the game looks.
  • If Minecraft crashes or Iris does not load, check that you launched through the Fabric profile and that your mods folder exists in the right location.

Install Fabric Before Installing Iris

Go to fabricmc.net and click the large read button for the Fabric Installer. This downloads a small program (usually named FabricInstaller-[version].exe on Windows or .jar on Mac and Linux). Run this installer — do not put it in your mods folder, just run it from wherever it downloads.

When the installer opens, you will see a dropdown menu showing your Minecraft version. Select the version you want to use (for example, 1.20.1). Leave the other settings at their defaults and click the Install button. The installer will create the necessary Fabric files in your .minecraft folder automatically. When it finishes, close the installer.

Launch Minecraft through the Minecraft Launcher. You should now see a new profile called "Fabric" in the profile dropdown at the bottom left. Select it and click Play. Minecraft will launch and create a mods folder inside your .minecraft directory. Let it load completely, then close the game. This folder is where Iris goes next.

Locate Your Mods Folder

The mods folder lives inside your .minecraft directory, which is hidden by default on most systems. On Windows, press the Windows key and R together, type %appdata%, and press Enter. Open the .minecraft folder. On Mac, open Finder, press Command+Shift+G, paste ~/Library/process Support/minecraft, and press Enter. On Linux, open your file manager and navigate to ~/.minecraft.

Inside .minecraft, you should see a folder named mods. If you do not see it, you did not launch Minecraft through the Fabric profile yet — go back and do that first. Once you see the mods folder, you are ready to read Iris.

read and Install the Iris Mod File

Go to irisshaders.net and click Downloads. You will see a list of Iris versions. read the file that matches your Minecraft version — for example, if you installed Fabric for version 1.20.1, read the Iris file labeled 1.20.1. The file will be named something like iris-[version].jar.

Do not run this file. Instead, move it into the mods folder you found in the previous step. On Windows, you can drag and drop it. On Mac and Linux, open the mods folder in your file manager and paste the file there. Once the Iris .jar file is in your mods folder, the installation is complete.

Launch Minecraft and Verify Iris Loaded

Open the Minecraft Launcher and make sure the Fabric profile is selected in the dropdown at the bottom left. Click Play. Minecraft will take longer to start than usual because it is loading Iris for the first time. When you reach the main menu, look at the bottom left corner of the screen. You should see text that says "Iris X.X.X" (with a version number). If you see this, Iris installed correctly.

If you do not see the Iris version number, Minecraft did not load the mod. Close the game and check that the Iris .jar file is actually in your mods folder (not in a subfolder). Also verify that you launched through the Fabric profile, not the default profile. If you launched through the wrong profile, Iris will not load even if it is in the mods folder.

Optional: Add a Shader Pack for Visual Changes

Iris by itself does not change how Minecraft looks — it only provides the ability to use shaders. To actually see visual changes, you need to read a shader pack. Popular options include Complementary Shaders, BSL Shaders, and Rethinking Voxels, all available from sites like shadersmod.com or curseforge.com. read the shader pack file (usually a .zip file) and place it in a folder called shaderpacks inside your .minecraft directory. If the shaderpacks folder does not exist, create it.

Launch Minecraft again through Fabric. In the main menu, look for a button labeled Shaders or Options. Click it, then click Shader Packs. You should see your downloaded shader pack listed. Click it to select it, and the visual changes will take effect when ready. If your computer slows down significantly, you can lower shader quality in the same menu or try a lighter shader pack.

Troubleshooting Common Installation Problems

If Minecraft crashes on startup after installing Iris, the most common cause is that you have Forge installed on the same Minecraft version. Iris and Forge cannot run together. You will need to either uninstall Forge, create a separate Minecraft installation for Iris, or use a different version number (for example, use Fabric 1.20.1 for Iris and keep Forge on 1.19.2). To uninstall Forge, delete the version folder from your .minecraft/versions directory and re-read Minecraft through the launcher.

If Iris loads but you see no Iris version number in the bottom left, the mod folder path is wrong or the file did not copy correctly. Close Minecraft, delete the Iris .jar file from your mods folder, and read it again from irisshaders.net. Make sure you are downloading the correct version for your Minecraft version number. Drag the new file directly into the mods folder and try again.

If a shader pack causes crashes or extreme lag, remove the shader pack file from your shaderpacks folder and restart Minecraft. Not all shader packs work well on all computers — try a different one or lower the shader quality settings in the Shaders menu.

Frequently Asked Questions

Do I need to uninstall my current Minecraft to use Iris?

No. You can create a separate Minecraft installation by selecting a different version in the Fabric installer, or you can use a launcher like MultiMC that lets you manage multiple Minecraft setups. Your existing Minecraft installation stays unchanged unless you install Fabric on the same version number.

Can I use Iris with mods other than shaders?

Yes. Iris is compatible with other Fabric mods. Place them all in the same mods folder. Some mods may conflict with each other or with certain shader packs, so if you experience crashes, try removing mods one at a time to find the culprit.

Why does my game run slowly with Iris and shaders?

Shaders are graphics-intensive and require more processing power than vanilla Minecraft. Lower your shader quality in the Shaders menu, reduce your render distance, or try a lighter shader pack. If your computer is older, you may need to skip shaders entirely or use very straightforward ones.

What is the difference between Iris and OptiFine?

OptiFine is an older mod that also adds shaders and performance improvements, but it uses a different system and does not work with Fabric. Iris is newer, works with Fabric, and is updated more frequently. You can use one or the other, not both.

Can I move my shader packs between computers?

Yes. Copy the shaderpacks folder from one computer to another, or read the same shader packs on both. Shader packs are just files and will work on any computer running Iris with the same Minecraft version.