How to Install Fabric

Fabric is a mod loader — the layer that lets Minecraft run third-party code. It is not a mod, it adds no features, and installing it alone produces a game indistinguishable from vanilla.

It comes in two pieces that are easy to confuse. Fabric Loader is what the installer puts in place, and it is what actually loads mods. Fabric API is a separate mod you download yourself, providing shared functionality that most Fabric mods depend on.

You need both. The installer gives you the first; the second you download from Modrinth like any other mod. Missing Fabric API is comfortably the most common Fabric install failure.

Go to fabricmc.net and take the installer for your operating system. Windows gets an .exe, macOS and Linux get a universal .jar you run with a double-click or from a terminal.

Open it and you get a small window with three fields. Minecraft Version is the one that matters — set it to the version you intend to play, and untick 'Show snapshots' so the list stays sensible. Loader Version should be left at the newest entry. Install Location will already point at your Minecraft folder unless you installed the game somewhere unusual.

Leave 'Create profile' ticked and click Install. It finishes in a couple of seconds and adds a profile to the official launcher rather than modifying anything you already have.

Open the Minecraft launcher. There will be a new profile named for Fabric and your version — select it from the dropdown next to Play.

Launch and wait for the title screen. This first run is what creates the mods folder, which is why hunting for that folder immediately after installing produces nothing.

Quit once you have seen the title screen. Nothing will look different, which is correct.

If no Fabric profile appears in the launcher, the launcher was open while the installer ran. Close it completely, reopen, and it will be there.

Fabric API is on Modrinth. Open its page, set the version filter to your Minecraft version, and download the matching file.

It is a .jar. Put it in the mods folder alongside everything else — it is installed exactly like a mod, because it is one.

Getting the version wrong here produces a confusing failure: mods report that Fabric API is missing even though the file is clearly present. It is present but built for a different Minecraft version, so the loader ignores it.

On Windows, press Win+R and paste %appdata%\.minecraft. On macOS, Finder then Cmd+Shift+G then ~/Library/Application Support/minecraft. On Linux, ~/.minecraft.

The mods folder is inside. Drop .jar files in with the game closed.

If you use Prism Launcher or MultiMC, each instance has its own mods folder and the .minecraft one is irrelevant. Use the launcher's folder button.

Fabric is worth installing mainly because of what runs on it. These four take five minutes, change nothing about gameplay, and make the game meaningfully better.

Sodium rewrites rendering and is the single largest frame-rate gain available in Minecraft. Lithium optimises game logic with no configuration and no visual change. Iris adds shader support and works with Sodium, which is what replaced OptiFine for most people. Mod Menu gives you an in-game list of your mods and access to their settings, which Fabric otherwise lacks entirely.

None of them add blocks or items, so none of them can damage a world. That makes this a genuinely safe first mod list.

Launch the Fabric profile again. The title screen should now show a mod count in the corner. Open Mods from the main menu — added by Mod Menu — and you should see everything listed.

If the game opens with no mod count and no Mods button, you almost certainly launched the vanilla profile. Check the dropdown.

If it crashes, read the first error in latest.log rather than the last. On a fresh Fabric install the cause is nearly always a version mismatch on one file, and the log names it.

Pin the Minecraft version in the launcher's installation settings rather than leaving the profile on latest-release. Auto-update is the most common reason a working Fabric setup breaks overnight.

When you do update to a new Minecraft version, re-run the Fabric installer for that version and re-download every mod. Mods are version-specific and none of them carry over.

Keep a note of which mod versions worked together. It costs nothing and saves an hour the next time something breaks.

The client installer has a server mode, and the process differs enough to be worth spelling out.

Run the same installer, switch to the Server tab, choose your Minecraft version and pick an empty folder. It downloads a server launcher into that directory. Run it once and it will stop immediately, having written eula.txt.

Open that file, change false to true, and start it again. The world generates and the server is running.

Then add mods to the server's own mods folder, which is inside the server directory and entirely separate from your client's. Server-side mods must match client-side mods for anything that adds content — same versions, same loader. Client-only mods like Sodium and Iris are never installed on a server.

A lot of people arrive at Fabric because OptiFine stopped working for them, and the transition is not one-to-one.

OptiFine bundled several unrelated features into one download: rendering optimisation, shader support, dynamic lighting, zoom, connected textures and capes. On Fabric these are separate mods, which is more installing but far better compatibility.

Sodium replaces the rendering optimisation. Iris replaces the shader support. Zoomify or Ok Zoomer provides the zoom key. Continuity handles connected textures, and LambDynamicLights handles dynamic lighting.

Install Sodium and Iris first, and add the others only if you actually used those features. Most people find they used two of the six.

OptiFine itself does have a Fabric-compatible route via OptiFabric, but it conflicts with a great many mods and is not worth the trouble on a fresh setup.

Three mistakes account for most first-time Fabric failures, and all three produce misleading symptoms.

Installing Fabric API for the wrong Minecraft version is the most common. Mods report it as missing even though the file is visibly in the folder, because the loader ignores a build that does not match.

Putting mods in .minecraft/mods while running a Prism or MultiMC instance is the second. The instance has its own folder and never reads the default one, so nothing loads and nothing errors.

Leaving the launcher profile on latest-release is the third, and it is a delayed fault: everything works until Minecraft updates, then the loader no longer matches and the whole setup fails at once.

When a new Minecraft version arrives, a Fabric setup does not carry over. Every piece of it is version-specific and has to be replaced.

Re-run the Fabric installer and select the new Minecraft version. This creates a second profile rather than replacing the old one, which is deliberate — keep the working profile until the new one is proven.

Then download fresh builds of every mod. Fabric API first, then the rest. Mods for the previous version will not load, and leaving them in the folder produces a wall of errors that obscures anything genuinely wrong.

The cleanest approach is a new mods folder rather than editing the old one. Point the new profile at its own directory using the launcher's game-directory setting, or use an instance-based launcher where this separation is the default.

Give it a week or two after a Minecraft release before bothering. Fabric Loader itself updates within days, but the mods you actually want take a little longer, and updating into a half-ported ecosystem is frustrating.