Minecraft Java 1.21 Mods
Browse 94 free mods for Minecraft Java 1.21 — popular picks include Simple Mermaid Tails, Better Sea Lantern Crafting, ClimateCraft.
Updated daily

Simple Mermaid Tails
This Mod adds Mermaid Tails, thats it. This is kinda a fork from my Mako Mermaids Mod but without the Powers etc.
Better Sea Lantern Crafting
This datapack/mod allows you to craft Sea Lanterns in a better way
ClimateCraft
Adds climate change mechanics. Building, mining, and smelting emit CO2, plants absorb it. Keep the environment in balance or suffer sea level rise, droughts, and wildfires!
Monster Origins
(WIP) Minecraft 1.20.1 (and now 1.21.1) / Fabric addon for Origins that adds four origins Arachne (a humanoid spider), Medusa (a gorgon), Harpy (a storm-wind bird-woman), and Mermaid (a singer of the deep) each built around a different playstyle
Poseidon - Underwater Survival
Shipwrecked and stranded underwater. Breathe, build, and survive in a fully aquatic island world.
Lava Oceans
simple datapack that makes all oceans lava
Water Enhanced
Expands ocean gameplay with new resources, gear, and aquatic mechanics while staying true to vanilla.
Drown Panic
"An immersive mod that enhances survival atmosphere underwater with a wide screen vignette (tunnel vision) and realistic heartbeat sounds when drowning."
Overworld - End Sea [Create Aeronautics]
This project adds an Aeronautics End Sea to the Overworld
Breathe Underwater
A simple mod to let you breath under water without any potion effect Theres many dangers already, dont let the sea be other
Aquatic Creatures
Did you know we know most about the space than own ours oceans? I want to make you feel that with this mod
Stay Flooded!
A mod that prevents air pockets from forming when submerged blocks are destroyed, perfect for an aquatic playthrough :-)
Toads Simple Origins: Fish Bowl
Adds a custom piece of armor that allows custom origins datapacks to add a way to spend more time on land or in the nether without completely removing the challenge of only breathing underwater.
Nauseous Lite
Enchanced and customized nausea effects
DrownForReal
Drown For Real adds realistic player panic animations when your underwater oxygen bar hits zero. Built for Fabric, it features custom flailing animations that smoothly blend in and out over a fraction of a second using player-animation-lib.
sharky's random ideas
my most random, wierdest and funny ideas
Underwater Torch
Place all torches underwater and they will still emit light Full Fabric 1.20.1 + 1.21.1 + 1.21.4
Aqua Verse
AquaVerse expands aquatic biodiversity of minecraft
Splinecart Aquatic
This is a small mixin designed to be used with the Splinecart mod. It makes Splinecart track ties able to be placed in water, that way you can make under water roller coasters or waterslides.
No Boats
This mod removes all boats from Minecraft, forcing you to travel across water the slow way. It makes oceans feel bigger and exploration harder since you can’t just zip across huge distances anymore.
Aquatica - 0.1 Actual Fishing
This datapack aims to add to the aquatic regions of Minecraft. The 0.1 version overhauls the fishing system.
FishMating
Bring your underwater world to life by letting fish breed naturally when players throw seeds into water! 🌊🐠✨
DrownedOverhaul – A Deep Sea Threat Awaits
DrownedOverhaul transforms Minecraft’s oceans into a place of genuine peril. This plugin completely reimagines the behavior of Drowned mobs, turning them from passive nuisances into coordinated threats lurking beneath the waves.
[Aeronautics] Overworld End Sea
Enables Create Simulated/Aeronautics' End Sea mechanic in the overworld, for void-accessible worldgen
AirBreather
Breathe underwater with a customizable Air Mask!
Special Potions
Adds new powerful potions with unique abilities like Fire, Ocean, Wind, Warden, Ender, Speed, and Strength effects for survival and PvP gameplay.
AquaLib
AquaLib is the foundational core library engineered to power the Aqua Kingdoms ecosystem and its suite of advanced oceanic features. It provides a high-performance framework for handling complex data and immersive underwater mechanics while ensuring best
vegan-fishing
A Fabric mod for Minecraft Java 1.21.11 that replaces the fish loot table with plant-based and ocean-themed alternatives, allowing players to enjoy the relaxing fishing minigame without harming any virtual wildlife.
Unsafe Water
Now if you swim in river, sea or ocean you will take damage.
Nuclear sewage-核污水
This is a data pack that can be used for island survival, players will get poison and nausea when they touch water, and after drinking the water lung potion, they will be immune to poison and nausea, and of course, players can take a boat without harm!
SIF (Sharked Invisible Frames)
Just a plugin that makes frames invisible when you right-click shears
CarrotSkin
In-game HUD with fancy carrots, custom exhaustion bar and relocated underwater bubbles to display above hp.
Under The Seas
Discontiued For Certain Amount Of Time A new gameplay to minecraft by exploring the darkness of the sea
Chewing Gum
This mod adds a pack of gums with 3 pieces inside used to remove nausea
Bonemeal Renewable Coral
Bonemealing coral blocks spreads them in a warm ocean.
Toasts Abilities
A data pack that adds 7 different custom classes, each with a ability, ultimate and a passive to improve combat. They are: Wind, Electric, Space, Sculk, Life, Metal and Oceanic