Bulletpies · wiki

Step by step

How to install a mod

Written for someone who has never done this. It takes about ten minutes the first time and about thirty seconds every time after that.

ℹ️ Java Edition only

These steps are for Minecraft Java Edition on PC. If you play on a phone, console or the Windows Store version, skip to Bedrock add-ons.

🧮 Step 1: Check the mod's two numbers

Open the mod's page here and look at the bar under the title. It gives a loader (NeoForge, Forge or Fabric) and a Minecraft version (like 1.21.1). Note both down. Everything else depends on getting these two right.

⬇️ Step 2: Install that loader

  1. Run the official Minecraft launcher once on the exact version you want (for example 1.21.1) and let it reach the title screen. This creates the files the loader needs.
  2. Download the installer for your loader from its own official site, choosing the same Minecraft version.
  3. Run the installer and choose Install client.
  4. Reopen the Minecraft launcher. A new profile appears in the bottom-left dropdown and you should select it and press Play once to confirm it boots.

🧩 Fabric users, one extra file

Fabric mods almost always also need Fabric API, which is itself a mod. Download it and put it in the same mods folder in the next step.

📁 Step 3: Find your mods folder

Running the loader once creates it automatically. To get there quickly:

Inside is a folder called mods. If it is not there, create one with exactly that name.

📦 Step 4: Drop the jar in

Mods are .jar files. Put the file straight into mods. Do not unzip it, do not put it in a subfolder, do not rename it. Then launch the game using the loader profile. If it worked, the mod is counted on the title screen's mods list.

💾 Step 5: Back up your world first. Really.

Mods write extra data into your save file. Removing a mod later can leave a world that will not open. Backing up takes ten seconds:

  1. Go to .minecraft/saves.
  2. Copy the folder named after your world.
  3. Paste it somewhere else and add "backup" to the name.

⚠️ Most of these mods have never been playtested

Every mod page says which. Try them on a fresh world, or on a copy, before letting one anywhere near a survival world you care about.

👥 Step 6: Playing with friends

Each mod page has a Who installs it box. Usually everyone on the server needs the same mod at the same version, and the server needs it too. A few are client-side only, and those you can use on any server without asking anyone.

📱 Bedrock add-ons

Bedrock Edition (phone, tablet, console, Windows Store) does not use jars or loaders. It uses add-ons, packaged as .mcaddon files. Download one and open it, and Minecraft imports it by itself. Then, when creating a world, switch the behaviour pack and resource pack on in the world settings, and enable Experimental Features if the add-on's page says to. Add-ons apply per world, not globally.

💥 When it does not work

What you seeWhat it usually means
Crashes instantly on launchLoader or Minecraft version does not match the mod. Check both numbers again.
"Missing dependency" error screenThe mod needs another mod. Fabric API is the usual answer; a couple of mods here depend on each other and say so on their page.
Game loads, mod does nothingWrong profile selected in the launcher, or the jar landed in the wrong folder.
World will not open after removing a modRestore your backup. This is what step 5 is for.
Kicked when joining a friendThe server and every player need the same mods at the same versions.

Pick a mod → Confused by a word?