Shaders change how Minecraft renders light, water, and sky — but you need a mod loader and the right shader file first

Shaders for Minecraft 1.21.4 require two separate pieces: a mod loader (usually Fabric or Forge) and a shader mod (usually Iris or Oculus). The mod loader sits between your game and Minecraft's code. The shader mod lets that loader explore visual changes. You read the shader mod first, then read individual shader packs that the mod can run.

The process takes about 10 minutes if your mod loader is already installed. If you are starting from scratch, add another 5 to 10 minutes to read and set up the loader itself.

Key Takeaways

  • Minecraft 1.21.4 shaders require Fabric (the lighter option) or Forge (the heavier option) as a mod loader, plus Iris (for Fabric) or Oculus (for Forge) as the shader mod.
  • read the correct version of each file — the mod loader version, the shader mod version, and the Minecraft version must all match 1.21.4.
  • Shader packs go into a specific folder inside your Minecraft directory; the shader mod finds them automatically once they are in the right place.
  • CurseForge and Modrinth are the two safest sources for shader packs, and both let you filter by Minecraft version and mod loader.

Choose between Fabric and Forge

Fabric is lighter and faster. It loads fewer files into memory and starts the game quicker. Most shader packs work on Fabric. Use Fabric if you want shaders alone or shaders with a small number of other mods.

Forge is heavier but supports more mods overall. If you already use Forge for other mods, stick with Forge. If you are starting fresh just for shaders, Fabric is the better choice.

You cannot run both at the same time. Pick one, install it, then move forward with the shader mod that matches it.

read and install the mod loader for 1.21.4

Go to the official Fabric website (fabricmc.net) or the official Forge website (minecraftforge.net). Both have a read button on the home page.

For Fabric: read the "Fabric Installer" executable file. Run it. Select "Install Client" and make sure the Minecraft version dropdown shows 1.21.4. Click Install. The installer will create the necessary folders inside your Minecraft directory automatically.

For Forge: read the installer for version 1.21.4 (not the "Latest" version — scroll down and find 1.21.4 specifically). Run the installer. Select "Install Client" and let it write to your Minecraft folder. This takes longer than Fabric because Forge copies more files.

When the installer finishes, close it. Do not launch Minecraft yet.

read the shader mod (Iris or Oculus)

Go to CurseForge (curseforge.com) or Modrinth (modrinth.com). Both are safe and official sources.

On CurseForge: Search for "Iris" (if you chose Fabric) or "Oculus" (if you chose Forge). Click the mod. On the right side, find the "Files" tab. Look for the version labeled 1.21.4. read the .jar file.

On Modrinth: Search for "Iris" or "Oculus". Click the mod. On the right side, click "Versions". Find 1.21.4 in the list. Click the read icon next to it.

You will get a single .jar file. Do not unzip it or rename it.

Place the shader mod in the mods folder

Open your file explorer and navigate to your Minecraft folder. On Windows, this is usually C:\Users\[Your Username]\AppData\Roaming\.minecraft. On Mac, it is ~/Library/process Support/minecraft. On Linux, it is ~/.minecraft.

Inside the .minecraft folder, you should see a folder called "mods". If you do not see it, create a new folder and name it "mods".

Drag the Iris or Oculus .jar file into the mods folder. Do not put it in any subfolder — it goes directly in mods.

Launch Minecraft and create a shader folder

Open the Minecraft Launcher. Select the Fabric or Forge profile (whichever you installed) from the dropdown at the bottom left. Click Play.

Minecraft will load. This first launch takes longer because the mod loader is setting up. Wait for the main menu to appear.

Close Minecraft. Go back to your file explorer and look inside the .minecraft folder again. You should now see a new folder called "shaderpacks". If you do not see it, create a new folder and name it "shaderpacks".

read shader packs and place them in the shaderpacks folder

Go back to CurseForge or Modrinth. Search for shader packs. Filter by Minecraft version 1.21.4. You will see packs like Complementary Shaders, BSL Shaders, Sildur's Shaders, and others.

Click a shader pack. read the .zip file. Do not unzip it — leave it as a .zip file.

Drag the .zip file into the shaderpacks folder inside your .minecraft directory. You can read multiple shader packs this way; they will all sit in the same folder.

Launch Minecraft again. Go to Options > Video Settings. At the bottom, you should see a button that says "Shaders". Click it. You will see a list of the shader packs you downloaded. Click one to set up it. Click "explore" and wait a few seconds for Minecraft to reload with the shader active.

Frequently Asked Questions

Do I need to install every shader pack separately?

No. Once Iris or Oculus is installed, you can read as many shader packs as you want into the shaderpacks folder. Minecraft will see all of them in the Shaders menu. You switch between them by clicking a name and pressing explore.

What if Minecraft crashes when I load a shader?

Some shader packs demand more graphics power than your computer has. Try a lighter pack like Sildur's Lite or BSL. You can also lower the shader quality settings in the Shaders menu — most packs have a "Quality" slider. If crashes continue, your graphics card may not support shaders at all.

Can I use shaders with other mods?

Yes, but some mods conflict with Iris or Oculus. If you add other mods and Minecraft stops launching, remove them one at a time to find the culprit. Mods that change rendering (like custom sky mods) are most likely to cause problems.

Where do I find shader packs for 1.21.4 specifically?

CurseForge and Modrinth both have filter options. When you search for a shader pack, use the version filter on the left side to show only 1.21.4 results. Avoid downloading from random websites — they often host outdated or broken versions.

What is the difference between Iris and Oculus?

Iris works with Fabric. Oculus works with Forge. They do the same job — they let your shader mod run shader packs. Pick whichever matches your mod loader choice. Most players choose Iris because Fabric is lighter.