Minecraft Java 1.21 Mods
Browse 3,588 free mods for Minecraft Java 1.21 — popular picks include TritiumConfiguration, VS Unofficial Neoforge Port, Abstract Operations.
Updated daily
TritiumConfiguration
A lightweight configuration library for multi-mod-loader platforms with multi-MC-version support, designed for new developers and those who want to streamline their workflow.
VS Unofficial Neoforge Port
An unofficial NeoForge port of the Valkyrien Skies 2 physics engine to Minecraft 1.21.1.
Abstract Operations
Json <-> NBT interchange library
Iskandert's Library
A library of functions used primarily by Iskandert's Team mods
Rage Mod
Add "Rage" to entities. Get damage bonus on full rage.
ValorlessUtils [1.18-26.2]
Utility library for easier plugin development.
GrieferGames CustomBlocks
Customblocks for GrieferGames and Bausucht Citybuild Server
SimpleCloud API Plugin
This Project aims to provide very easy API access for all SimpleCloud APIs
Version't
A powerful java reflection layer and toolchain targeted at multi-version Minecraft Fabric modding
Jsonate
Jsonate simplifies Minecraft mod configuration with a lightweight JSON API, automating versioning, file handling, and type-safe data access for Forge developers.
Burning Block
The mod that makes fire mechanics more believable!
CAWEZ'S Mantle to Stratus
A vertical expansion to Minecraft adding 3 new dimensions both above and below the Overworld, with many sights to see and challenges to overcome.
Vivecraft Spigot Extension
Adds support for Vivecraft on Spigot/Paper/Folia based servers

AriKeys
AriKeys is a client-side mod for Minecraft, which allows your client to receive and send keypresses between servers using the AriKeys plugin.
Burning Block TFC
TFC compat for the mod that makes fire mechanics more believable!
Bobo Lib
A library mod for Bobophones mods
Matthiesen Core
A library mod for NeoForge and Fabric that enables developers to create mods with a shared common codebase.
Mowzie's Mobs definitive [Mutant Monsters Compat]
This is a mod for a modpack called Mowzie's Mobs that will add compatibility for Mutant Monsters. It will include changing the mutant zombie model to geckolib, making it easy to modify the animations and model with Kube.js or resource packs.
Quark Zeta Fixin
Fixes a race condition in Zeta, the library for Quark, that occurs when too many addons are installed
Wynnic Enchantments Helper
A helper mod for Wynnic Enchantments modpack
SLM: Elements
Add an advanced elemental and elemental damage system, with direct, inverse, and static interactions and more!

Spear Core
A lightweight library mod that provides a complete spear weapon system for Minecraft 1.21.1 NeoForge.
SDM Loot Stages
Create a step-by-step progression for loot tables!
Wilderness Odyssey API
this is a mod made for the modpack wilderness odessy. it has lots of tools and things in it. and others can use it too
HZLib
The shared library powering all Heria Zone mods. Provides the multi-loader entity framework, variant system, animation profiles, and platform services that every Heria Zone mod is built on.
easierworldcreator
library mod that help you creating features by generating 3d shapes
Radioactive
Unified radiation for modpacks and servers.
KubeJS Create Automation
An automation hook mod that bridges Create machines with KubeJS, allowing pack makers to intercept and customize automated actions through scripts.
Ashen Legion
Legion/Horde encounters, Data Driven!

BetterConfig
A very powerful and easy to use command based configuration library for servers and clients.

Spark Core
A lib mod with rigid body physics, bedrock version of animation loader, state machine and other useful content.
NovaCoreTempFix-421856
Temporary fixed updates for NovaCore only for 1.21.1
AcornLib
An API with features to make modding easier, including new Components, Particles, Weapon Skins, and Supporter Perks.
MapEngine
MapEngine is a map library plugin for minecraft paper servers, used to show images and video/streaming on maps
Middle-Earth Additions: Factions
A powerful addon for the Middle-Earth mod that provides seamless integration with PlaceholderAPI
CitFancy
Enable OptiFine CIT textures on Fabric using Fabric API