Is Iris free in Minecraft?

Yes. Iris is a free, open-source mod that adds shader support to the Fabric loader.

Can Iris be installed with Forge?

No. Iris is built for Fabric only and will not run on Forge. Forge players need OptiFine or a similar alternative instead.

Does Iris need Sodium?

Yes, Iris requires the Sodium performance mod in the same mods folder. The two are developed to work together.

Do OptiFine shaders work with Iris?

Most of them do. A small number of packs use OptiFine-only features and are incompatible; the Iris project keeps a list of those on its GitHub page.

How to Install Iris Shaders in Minecraft

There are two big ways to run shaders in Minecraft: OptiFine, the old classic, and Iris, the modern Fabric-based loader that most players have switched to. Iris is fast, updates quickly after new Minecraft versions, and works hand in hand with the Sodium performance mod. Here is the whole install, start to finish.

Before You Start

Iris is a Fabric mod, so you need the Fabric loader installed for your Minecraft version first. Iris also requires Sodium to run; without Sodium in the same folder, the game will complain on launch. Iris does not work with Forge at all, so if your modpack is Forge-based, this is not your loader. The good news: Iris itself is completely free.

Step 1: Download Iris

Open the Iris page on CurseForge or Modrinth.
Go to the Files or Versions tab.
Download the file that matches both your Minecraft version and the Fabric loader. Version mismatches are the number one cause of crashes, so read the file name carefully.

Step 2: Put the File in the Mods Folder

Open your .minecraft folder. On Windows, press Win + R and type %appdata%/.minecraft.
If there is no folder called mods inside, create one.
Move the downloaded Iris file, and your Sodium file, into the mods folder.
Launch the game using your Fabric profile. If the main menu loads, Iris is installed.

Step 3: Add and Enable Shaderpacks

Iris is the engine; you still need actual shaders to look at. Download a shaderpack from CurseForge or Modrinth and drop the zip, unopened, into the shaderpacks folder inside .minecraft. Then, in game:

Open Options, then Video Settings.
Open the Shader Packs tab (its presence confirms Iris is active).
Click your pack in the list and hit Apply.

Most shaderpacks written for OptiFine also run on Iris, which gives you a huge library to choose from, though a small number rely on OptiFine-only features and are listed as incompatible on the Iris GitHub page. If a beloved pack misbehaves, that list is the first place to check.

That is genuinely all there is to it. Fabric, Sodium, Iris, one shaderpack, and Minecraft goes from flat and functional to sunsets you will stop walking to look at.

Troubleshooting Common Iris Problems

Most failed Iris installs come down to one of three mismatches. First, version drift: the Iris file, Sodium file, Fabric loader, and Minecraft version must all agree, and a file grabbed for last month's update is the usual crash culprit. Second, a missing partner: Iris without Sodium in the mods folder will not start, and many shaderpacks quietly assume both. Third, folder confusion: the Iris file belongs in mods, but shaderpacks themselves go in the shaderpacks folder as untouched zip files; unzipping them is a classic way to make a pack vanish from the list. If the Shader Packs tab is missing from Video Settings entirely, the game launched with the wrong profile, so restart using your Fabric installation and check again. Get those four things right and Iris is, in practice, the most trouble-free way to run shaders in modern Minecraft.