Hello!
Here is an up-to-date list of Fabric mods focused on optimizing Minecraft's performance. The Fabric modloader was introduced after Minecraft 1.12.2, so there are no Fabric mods for versions earlier than 1.14. The mods listed below aim to improve game performance (FPS, loading times, server optimization, etc.) on Fabric. Each is presented with its function, supported versions, and possible dependencies. All are Fabric-compatible (some also have Forge/Quilt variants, but we’re focusing on Fabric only).
Client-side optimizations (rendering and FPS)
Sodium (MC 1.16.1+ – Client only)
Replaces Minecraft’s graphics rendering engine to significantly boost FPS without degrading visual quality. It’s one of the fastest and most compatible rendering optimization mods.
Versions supported: 1.16.1 to 1.21.x (regular updates ensure compatibility with the latest versions).
Dependencies: None required (Sodium works without Fabric API). However, to enable advanced rendering features on Fabric, it previously needed to be paired with Indium – but since Sodium 0.6.0, this compatibility is now built-in.
Indium (MC 1.16.5 to 1.20.x – Client)
Indium is an add-on for Sodium that used to provide support for Fabric’s rendering API (Indigo), which Sodium alone didn’t support. It was necessary for some graphics mods (e.g., dynamic lighting, shaders, connected textures, etc.) to work properly with Sodium.
Versions: 1.16.5 to 1.20.x (not compatible with Sodium 0.6+/MC 1.21).
Dependencies: Requires Sodium. Note: If using Sodium ≥0.6.0 (Minecraft 1.21+), Indium is no longer required or compatible, since Sodium now includes Fabric API support natively.
Sodium Extra (MC 1.16.5+ – Client)
A complementary add-on to Sodium that adds extra settings and features not included in base Sodium. For example, it offers an enhanced video options menu (sorted settings, zoom control, fine-tuning of visual details, etc.) and optional optimizations (particle toggling, entity render distance control, etc.) to better adjust performance.
Versions: 1.16.5+ (including 1.21.x).
Dependencies: Requires Sodium to function (be sure to install the version of Sodium Extra that matches your Minecraft/Sodium version). Sodium Extra makes it easier to fine-tune Sodium for even greater FPS gains based on your needs.
ImmediatelyFast (MC 1.18.2+ – Client)
Optimizes Minecraft’s “immediate mode” rendering – that is, all draw calls that used the old OpenGL immediate pipeline. This mod batches and optimizes those calls to reduce GPU load. In practice, ImmediatelyFast accelerates rendering for entities, special blocks (block entities), particles, text, and UI by batching draw calls and limiting costly render operations.
Versions: 1.18.2 to 1.21.x (Fabric or other loaders).
Dependencies: None required (lightweight and standalone). Compatible with Sodium and most mods (designed to be “plug-and-play” alongside the existing rendering engine).
Enhanced Block Entities (EBE) (MC 1.16.2+ – Client)
Optimizes the rendering of block entities (chests, signs, heads, spawners, etc.), which can cause FPS drops when present in large numbers. EBE replaces the traditional rendering of these special blocks with pre-baked models when possible, greatly reducing their performance impact while retaining their animations and sometimes improving lighting. Result: less rendering lag from block entities, with no major visual compromises.
Versions: 1.16.2 to 1.21.x (recently updated for 1.21).
Dependencies: Fabric API is required. If using Sodium, make sure to use EBE ≥0.10.2 and Sodium ≥0.6 for direct compatibility (older versions required the Indium add-on, but that’s no longer necessary since Sodium 0.6).
Entity Culling (MC 1.16+ – Client)
Uses an asynchronous path-tracing algorithm to avoid rendering entities and blocks that are outside the player’s field of view. Normally, Minecraft wastes resources rendering invisible entities/tiles (behind walls, underground…). This mod efficiently calculates visibility and hides anything occluded, reducing GPU and CPU load. The FPS gain can be substantial, especially in entity-heavy areas.
Versions: 1.16.x to 1.21.x.
Dependencies: None (compatible with Fabric API but not required).
Note: Entity Culling works very well alongside Sodium to further boost rendering, and can be finely configured via a config file or Mod Menu.
More Culling (MC 1.18+ – Client)
This mod extends culling techniques (selective rendering) to various parts of the game to improve performance. Minecraft already includes basic culling (hidden block faces, etc.), but More Culling goes further: it culls inner leaf faces (like Optifine’s “Smart Leaves”), invisible parts of blocks, certain offscreen entities, and more – reducing the number of elements that need to be rendered.
Versions: 1.18.x to 1.21.x (very active mod, updated for recent versions).
Dependencies: Cloth Config is required to configure the mod (Fabric API recommended). Be sure to install Cloth Config for More Culling to function properly. (Note: The author also provides MoreCullingExtra, an optional addon for even more aggressive culling optimizations.)
Dynamic FPS (MC 1.14.4+ – Client)
This mod automatically reduces resource usage when Minecraft is not in the foreground or the player is inactive. In practice, Dynamic FPS caps the frame rate when you Alt-Tab or the window is in the background, and can also lower FPS while AFK. This eases the load on CPU/GPU and saves energy (especially useful for laptops on battery). As soon as you return to the game, the frame rate goes back to normal.
Versions: 1.14.4 to 1.21.x (regularly maintained).
Dependencies: None (optionally Cloth Config + Mod Menu to access in-game settings). This is a purely client-side mod, with no effect on the server.
Game engine optimizations (server & gameplay)
Lithium (MC 1.16.2+ – Client & Server)
A general-purpose optimization mod for Minecraft's internal systems. Lithium improves the performance of many core mechanics without altering gameplay: block physics, mob behavior, block/entity ticking, and more. It works both server-side (for better TPS) and client-side (singleplayer includes an internal server) and often brings over 50% improvements in tick times. In practice, it enables more complex redstone, more active entities and players without lag, and even in singleplayer you’ll notice smoother performance thanks to server thread relief.
Versions: 1.16.2 to 1.21.x (available for all recent Fabric versions).
Dependencies: None (does not require Fabric API or any libraries). Often the first mod to install for a Fabric server, and fully compatible with other optimization mods like Sodium and Phosphor.
Phosphor (MC 1.14.4 – 1.18.x – Client & Server)
Optimizes Minecraft’s lighting engine (light propagation calculations), one of the slowest parts of the game. With Phosphor, chunk generation becomes faster and large chunk load freezes are significantly reduced. It does not change any visible lighting behavior – it just recalculates lighting updates more efficiently.
Versions: 1.14.4 to 1.18.x (a version also exists for 1.19, but starting with 1.19+ its usefulness decreased as Mojang improved the lighting engine and alternatives emerged).
Dependencies: None (Phosphor doesn’t even require Fabric API according to its docs).
Note: Phosphor is no longer actively maintained (project archived) and has been replaced by Starlight (see below) on newer versions.
Starlight (MC 1.17 – 1.20.4 – Client & Server)
A complete from-scratch rewrite of Minecraft’s lighting engine, even more advanced than Phosphor. Starlight entirely reworks how light is calculated and stored, fixing many lighting bugs and dramatically accelerating chunk lighting generation. Starlight outperforms Phosphor (up to +90% speed compared to vanilla) while also resolving shadow glitches and incorrect lighting.
Versions: 1.17.x to 1.20.4 (archived in 2024, last version for 1.20.4).
Dependencies: None (standalone).
Note: Since Starlight no longer receives updates past 1.20, a fork named ScalableLux now continues the project for newer versions.
ScalableLux (MC 1.21.x – Client & Server)
This is a fork of Starlight made for versions 1.21 and above. It brings the same lighting engine optimizations as Starlight, plus a few bugfixes and an option to parallelize light calculations (for very fast chunk generation). In short, ScalableLux restores the major performance boost for lighting updates on servers/clients in 1.21+, where original Starlight was no longer available.
Versions: 1.21.x (compatible with Fabric and NeoForge).
Dependencies: None (developed by a well-known Fabric modder, ishland, who also created Lithium and C2ME). If upgrading a server/pack from 1.20 to 1.21, be sure to replace Starlight with ScalableLux to retain lighting optimizations.
Krypton (MC 1.16.2+ – Client & Server)
Optimizes Minecraft’s network stack. Krypton speeds up connection and packet handling using improvements inspired by high-performance server projects (Velocity, Tuinity…). For example, it replaces some Netty handlers with ultra-optimized native code, consolidates packet flushes to reduce CPU overhead, and improves (de)serialization performance. The result: more efficient network traffic, more stable server ticks, and a small memory gain.
Versions: 1.16.2 to 1.21.x.
Dependencies: None. Krypton is primarily a server-side mod (most of the gain is server-based), but can also be installed client-side to optimize the client’s network layer. Though still marked WIP by the author, it is widely used and compatible with most mods.
Alternate Current (MC 1.16+ – Server)
Fully reimplements redstone dust logic to eliminate the lag it causes in vanilla Minecraft. Vanilla redstone performs an excessive number of redundant calculations and updates every tick, leading to TPS drops in complex contraptions. Alternate Current introduces a more efficient, non-recursive redstone signal propagation algorithm that calculates the final state of the network in a single pass instead of many. This can reduce redstone CPU load by up to 30×, while maintaining behavior nearly identical to vanilla (with only minor differences in update order).
Versions: 1.16.x to 1.21.x (available on Fabric, NeoForge, etc.).
Dependencies: None (standalone server mod). A must-have for creative or technical servers using lots of redstone. (Note: The author, Space Walker, is also a contributor to PaperMC; this mod is reliable and minimally invasive.)
Very Many Players (VMP) (MC 1.18+ – Server)
A Fabric server optimization mod specifically designed for high player counts. VMP reworks several internal server systems to scale better when dozens of players are online at once. For example, it uses more efficient data structures to track which chunks/entities need to be sent to which players (zone maps), optimizes entity collision checks, improves entity tracking and chunk packet handling (with optional rate limiting). It also introduces per-player render distances to dynamically reduce network load.
Versions: 1.18.x to 1.21.x (actively developed and recently updated).
Dependencies: None (standalone server mod).
Recommendation: Use VMP alongside Lithium for maximum performance. Lithium optimizes core systems, VMP handles extreme player load scenarios.
Clumps (MC 1.14.4+ – Server/Client)
A simple mod that groups XP orbs on the ground into a single orb instead of many separate entities. Lots of small XP orbs can cause lag (each is a separate entity). Clumps automatically merges nearby orbs into a single large orb worth the total XP, drastically reducing entity count. The player absorbs the entire XP amount at once upon contact.
Versions: 1.14.4 to 1.21.x (available on Fabric and Forge).
Dependencies: None.
Usage: On servers (1.17+), installing Clumps server-side is enough for it to work (clients don’t need it, unless in singleplayer where it should be in your Fabric instance). Very useful after mob farm bursts or big XP drops to prevent TPS/FPS drops.
C2ME (Concurrent Chunk Management Engine) (MC 1.17.1+ – Client & Server)
Speeds up chunk generation and loading by parallelizing these tasks across multiple threads. By default, Minecraft handles chunks mostly on a single thread, which is slow on modern multi-core CPUs. C2ME better utilizes multiple cores to load/generate chunks in the background, handling terrain, lighting, carving, etc., concurrently. This results in faster world generation, fewer lag spikes when exploring quickly, and the ability to support longer view distances or faster pregeneration on servers.
Versions: 1.17.1 to 1.21.x (actively developed by ishland, updated recently).
Dependencies: None required (Fabric API recommended).
Tip: Combine C2ME with Lithium and Starlight/ScalableLux for maximum effect. Note: C2ME is still experimental and may cause minor issues with some world-gen mods. Best tested on staging servers before production use.
Memory and loading time optimizations
FerriteCore (MC 1.16.5+ – Client & Server)
Optimizes Minecraft’s memory usage. FerriteCore changes how certain frequently duplicated objects (e.g., block states, models, biome data) are stored to reduce the overall RAM footprint. In modded setups, it’s highly effective at lowering RAM usage. For example, in the All of Fabric 3 pack, heap usage dropped from 1792MB to 984MB with FerriteCore (Hydrogen reached 1335MB in the same test, but it is no longer maintained).
Versions: 1.16.5 to 1.21.5 (kept up to date for all recent versions).
Dependencies: None. Works on both client and server (install on both sides for full benefit). Compatible with nearly everything. (Note: Redundant if you still use Hydrogen on older versions — they cover the same optimization.) Ideal for players with RAM issues or large Fabric modpacks.
Memory Leak Fix (MC 1.14.4 – 1.20.4 – Client & Server)
As the name suggests, this mod patches several memory leaks present in vanilla Minecraft (both client and server). Some vanilla routines fail to release memory properly, which over time leads to growing RAM usage, lag, or crashes (especially during repeated resource loads, dimension changes, etc.). Memory Leak Fix plugs these known leaks.
Versions: 1.14.4 to 1.20.4 (no 1.21 version yet at the time of writing).
Dependencies: None. Install on client and/or server depending on your needs.
Note: The author recommends using it with Lithium and FerriteCore for optimal performance and memory handling. If upgrading to 1.21+, look out for newer versions or alternatives, as vanilla updates may have addressed some leaks.
LazyDFU (MC 1.14 – 1.19.4 – Client & Server)
Speeds up game startup by deferring the initialization of the DataFixerUpper (DFU) system. DFU is used to convert old saves to newer formats, but Minecraft initializes it at every launch even if it’s not needed right away, causing a startup delay. LazyDFU changes this so DFU loads only when required (e.g., when loading an old world).
Versions: 1.14.x to 1.19.4 (as of 1.19.4+, Mojang has improved async DFU handling, reducing LazyDFU’s usefulness — hence no 1.20/1.21 versions).
Dependencies: None. Just drop it into /mods and enjoy faster startup times.
Smooth Boot (MC 1.16.1 – 1.19.x – Client & Server)
Improves Minecraft’s multithreaded loading by preventing CPU spikes during game or chunk loading. Vanilla tends to spawn too many worker threads at once on multi-core CPUs, which can overwhelm the OS scheduler and cause stuttering. Smooth Boot lets you limit and spread thread usage more evenly, resulting in smoother and more stable load times. While initial loading may take slightly longer in seconds, it avoids freezing and improves overall system responsiveness.
Versions: 1.16.1 to 1.19.x (archived; Mojang partly fixed this in 1.19.4).
Dependencies: None (configurable via config file or Mod Menu).
For Minecraft 1.20+: Smooth Boot is no longer updated, but a fork named ThreadTweak now handles thread behavior in 1.20/1.21. It continues the same idea — optimizing load thread scheduling — and is recommended if you're still experiencing thread-related issues on newer versions.
ModernFix (MC 1.16.5+ – Client & Server)
An all-in-one optimization mod that improves multiple performance aspects of modern Minecraft (1.16+). It includes fixes and optimizations for faster startup, world loading, reduced memory usage, and bug patches. ModernFix also includes Mojang fixes backported to older versions, optimizes asset loading, and optionally revamps the 3D model loader for more efficient on-demand loading. Tests on large modpacks like All The Mods 8 (Forge 1.18) show up to 2× faster startup and several GB less RAM used with ModernFix enabled.
Versions: 1.16.5, 1.18.2, 1.19.2, 1.19.4, 1.20.x, 1.21.x (wide support, actively maintained).
Dependencies: None (fully standalone, supports Fabric and Forge).
Note: Most of ModernFix’s gains shine in modded environments, but even near-vanilla installs benefit from faster startup and bug fixes. Fully compatible with other performance mods like Lithium, Sodium, Ferrite, etc.
DashLoader (MC 1.16.5 – 1.20.6 – Client)
Greatly accelerates game and resource loading by caching rendering data. On first launch with DashLoader, the mod lets Minecraft load assets normally (models, textures, etc.) and creates a cache. On subsequent launches, it reloads from this optimized cache instead of reprocessing everything, resulting in significantly faster startup. On large modded instances, this can save minutes.
Versions: 1.16.5 to 1.20.6 (no 1.21 version yet — project is awaiting a new maintainer).
Dependencies: None (but may conflict with some all-in-one mods — DashLoader v3.0 improves this by not caching unsupported mods).
Note: Best suited if you launch the game or switch packs/servers often. The first run will be slower (cache creation), but you’ll see clear benefits after. If it isn’t updated for 1.21+, keep an eye out for forks or alternatives.
Here is an up-to-date list of Fabric mods focused on optimizing Minecraft's performance. The Fabric modloader was introduced after Minecraft 1.12.2, so there are no Fabric mods for versions earlier than 1.14. The mods listed below aim to improve game performance (FPS, loading times, server optimization, etc.) on Fabric. Each is presented with its function, supported versions, and possible dependencies. All are Fabric-compatible (some also have Forge/Quilt variants, but we’re focusing on Fabric only).
Client-side optimizations (rendering and FPS)
Sodium (MC 1.16.1+ – Client only)
Replaces Minecraft’s graphics rendering engine to significantly boost FPS without degrading visual quality. It’s one of the fastest and most compatible rendering optimization mods.
Versions supported: 1.16.1 to 1.21.x (regular updates ensure compatibility with the latest versions).
Dependencies: None required (Sodium works without Fabric API). However, to enable advanced rendering features on Fabric, it previously needed to be paired with Indium – but since Sodium 0.6.0, this compatibility is now built-in.
Indium (MC 1.16.5 to 1.20.x – Client)
Indium is an add-on for Sodium that used to provide support for Fabric’s rendering API (Indigo), which Sodium alone didn’t support. It was necessary for some graphics mods (e.g., dynamic lighting, shaders, connected textures, etc.) to work properly with Sodium.
Versions: 1.16.5 to 1.20.x (not compatible with Sodium 0.6+/MC 1.21).
Dependencies: Requires Sodium. Note: If using Sodium ≥0.6.0 (Minecraft 1.21+), Indium is no longer required or compatible, since Sodium now includes Fabric API support natively.
Sodium Extra (MC 1.16.5+ – Client)
A complementary add-on to Sodium that adds extra settings and features not included in base Sodium. For example, it offers an enhanced video options menu (sorted settings, zoom control, fine-tuning of visual details, etc.) and optional optimizations (particle toggling, entity render distance control, etc.) to better adjust performance.
Versions: 1.16.5+ (including 1.21.x).
Dependencies: Requires Sodium to function (be sure to install the version of Sodium Extra that matches your Minecraft/Sodium version). Sodium Extra makes it easier to fine-tune Sodium for even greater FPS gains based on your needs.
ImmediatelyFast (MC 1.18.2+ – Client)
Optimizes Minecraft’s “immediate mode” rendering – that is, all draw calls that used the old OpenGL immediate pipeline. This mod batches and optimizes those calls to reduce GPU load. In practice, ImmediatelyFast accelerates rendering for entities, special blocks (block entities), particles, text, and UI by batching draw calls and limiting costly render operations.
Versions: 1.18.2 to 1.21.x (Fabric or other loaders).
Dependencies: None required (lightweight and standalone). Compatible with Sodium and most mods (designed to be “plug-and-play” alongside the existing rendering engine).
Enhanced Block Entities (EBE) (MC 1.16.2+ – Client)
Optimizes the rendering of block entities (chests, signs, heads, spawners, etc.), which can cause FPS drops when present in large numbers. EBE replaces the traditional rendering of these special blocks with pre-baked models when possible, greatly reducing their performance impact while retaining their animations and sometimes improving lighting. Result: less rendering lag from block entities, with no major visual compromises.
Versions: 1.16.2 to 1.21.x (recently updated for 1.21).
Dependencies: Fabric API is required. If using Sodium, make sure to use EBE ≥0.10.2 and Sodium ≥0.6 for direct compatibility (older versions required the Indium add-on, but that’s no longer necessary since Sodium 0.6).
Entity Culling (MC 1.16+ – Client)
Uses an asynchronous path-tracing algorithm to avoid rendering entities and blocks that are outside the player’s field of view. Normally, Minecraft wastes resources rendering invisible entities/tiles (behind walls, underground…). This mod efficiently calculates visibility and hides anything occluded, reducing GPU and CPU load. The FPS gain can be substantial, especially in entity-heavy areas.
Versions: 1.16.x to 1.21.x.
Dependencies: None (compatible with Fabric API but not required).
Note: Entity Culling works very well alongside Sodium to further boost rendering, and can be finely configured via a config file or Mod Menu.
More Culling (MC 1.18+ – Client)
This mod extends culling techniques (selective rendering) to various parts of the game to improve performance. Minecraft already includes basic culling (hidden block faces, etc.), but More Culling goes further: it culls inner leaf faces (like Optifine’s “Smart Leaves”), invisible parts of blocks, certain offscreen entities, and more – reducing the number of elements that need to be rendered.
Versions: 1.18.x to 1.21.x (very active mod, updated for recent versions).
Dependencies: Cloth Config is required to configure the mod (Fabric API recommended). Be sure to install Cloth Config for More Culling to function properly. (Note: The author also provides MoreCullingExtra, an optional addon for even more aggressive culling optimizations.)
Dynamic FPS (MC 1.14.4+ – Client)
This mod automatically reduces resource usage when Minecraft is not in the foreground or the player is inactive. In practice, Dynamic FPS caps the frame rate when you Alt-Tab or the window is in the background, and can also lower FPS while AFK. This eases the load on CPU/GPU and saves energy (especially useful for laptops on battery). As soon as you return to the game, the frame rate goes back to normal.
Versions: 1.14.4 to 1.21.x (regularly maintained).
Dependencies: None (optionally Cloth Config + Mod Menu to access in-game settings). This is a purely client-side mod, with no effect on the server.
Game engine optimizations (server & gameplay)
Lithium (MC 1.16.2+ – Client & Server)
A general-purpose optimization mod for Minecraft's internal systems. Lithium improves the performance of many core mechanics without altering gameplay: block physics, mob behavior, block/entity ticking, and more. It works both server-side (for better TPS) and client-side (singleplayer includes an internal server) and often brings over 50% improvements in tick times. In practice, it enables more complex redstone, more active entities and players without lag, and even in singleplayer you’ll notice smoother performance thanks to server thread relief.
Versions: 1.16.2 to 1.21.x (available for all recent Fabric versions).
Dependencies: None (does not require Fabric API or any libraries). Often the first mod to install for a Fabric server, and fully compatible with other optimization mods like Sodium and Phosphor.
Phosphor (MC 1.14.4 – 1.18.x – Client & Server)
Optimizes Minecraft’s lighting engine (light propagation calculations), one of the slowest parts of the game. With Phosphor, chunk generation becomes faster and large chunk load freezes are significantly reduced. It does not change any visible lighting behavior – it just recalculates lighting updates more efficiently.
Versions: 1.14.4 to 1.18.x (a version also exists for 1.19, but starting with 1.19+ its usefulness decreased as Mojang improved the lighting engine and alternatives emerged).
Dependencies: None (Phosphor doesn’t even require Fabric API according to its docs).
Note: Phosphor is no longer actively maintained (project archived) and has been replaced by Starlight (see below) on newer versions.
Starlight (MC 1.17 – 1.20.4 – Client & Server)
A complete from-scratch rewrite of Minecraft’s lighting engine, even more advanced than Phosphor. Starlight entirely reworks how light is calculated and stored, fixing many lighting bugs and dramatically accelerating chunk lighting generation. Starlight outperforms Phosphor (up to +90% speed compared to vanilla) while also resolving shadow glitches and incorrect lighting.
Versions: 1.17.x to 1.20.4 (archived in 2024, last version for 1.20.4).
Dependencies: None (standalone).
Note: Since Starlight no longer receives updates past 1.20, a fork named ScalableLux now continues the project for newer versions.
ScalableLux (MC 1.21.x – Client & Server)
This is a fork of Starlight made for versions 1.21 and above. It brings the same lighting engine optimizations as Starlight, plus a few bugfixes and an option to parallelize light calculations (for very fast chunk generation). In short, ScalableLux restores the major performance boost for lighting updates on servers/clients in 1.21+, where original Starlight was no longer available.
Versions: 1.21.x (compatible with Fabric and NeoForge).
Dependencies: None (developed by a well-known Fabric modder, ishland, who also created Lithium and C2ME). If upgrading a server/pack from 1.20 to 1.21, be sure to replace Starlight with ScalableLux to retain lighting optimizations.
Krypton (MC 1.16.2+ – Client & Server)
Optimizes Minecraft’s network stack. Krypton speeds up connection and packet handling using improvements inspired by high-performance server projects (Velocity, Tuinity…). For example, it replaces some Netty handlers with ultra-optimized native code, consolidates packet flushes to reduce CPU overhead, and improves (de)serialization performance. The result: more efficient network traffic, more stable server ticks, and a small memory gain.
Versions: 1.16.2 to 1.21.x.
Dependencies: None. Krypton is primarily a server-side mod (most of the gain is server-based), but can also be installed client-side to optimize the client’s network layer. Though still marked WIP by the author, it is widely used and compatible with most mods.
Alternate Current (MC 1.16+ – Server)
Fully reimplements redstone dust logic to eliminate the lag it causes in vanilla Minecraft. Vanilla redstone performs an excessive number of redundant calculations and updates every tick, leading to TPS drops in complex contraptions. Alternate Current introduces a more efficient, non-recursive redstone signal propagation algorithm that calculates the final state of the network in a single pass instead of many. This can reduce redstone CPU load by up to 30×, while maintaining behavior nearly identical to vanilla (with only minor differences in update order).
Versions: 1.16.x to 1.21.x (available on Fabric, NeoForge, etc.).
Dependencies: None (standalone server mod). A must-have for creative or technical servers using lots of redstone. (Note: The author, Space Walker, is also a contributor to PaperMC; this mod is reliable and minimally invasive.)
Very Many Players (VMP) (MC 1.18+ – Server)
A Fabric server optimization mod specifically designed for high player counts. VMP reworks several internal server systems to scale better when dozens of players are online at once. For example, it uses more efficient data structures to track which chunks/entities need to be sent to which players (zone maps), optimizes entity collision checks, improves entity tracking and chunk packet handling (with optional rate limiting). It also introduces per-player render distances to dynamically reduce network load.
Versions: 1.18.x to 1.21.x (actively developed and recently updated).
Dependencies: None (standalone server mod).
Recommendation: Use VMP alongside Lithium for maximum performance. Lithium optimizes core systems, VMP handles extreme player load scenarios.
Clumps (MC 1.14.4+ – Server/Client)
A simple mod that groups XP orbs on the ground into a single orb instead of many separate entities. Lots of small XP orbs can cause lag (each is a separate entity). Clumps automatically merges nearby orbs into a single large orb worth the total XP, drastically reducing entity count. The player absorbs the entire XP amount at once upon contact.
Versions: 1.14.4 to 1.21.x (available on Fabric and Forge).
Dependencies: None.
Usage: On servers (1.17+), installing Clumps server-side is enough for it to work (clients don’t need it, unless in singleplayer where it should be in your Fabric instance). Very useful after mob farm bursts or big XP drops to prevent TPS/FPS drops.
C2ME (Concurrent Chunk Management Engine) (MC 1.17.1+ – Client & Server)
Speeds up chunk generation and loading by parallelizing these tasks across multiple threads. By default, Minecraft handles chunks mostly on a single thread, which is slow on modern multi-core CPUs. C2ME better utilizes multiple cores to load/generate chunks in the background, handling terrain, lighting, carving, etc., concurrently. This results in faster world generation, fewer lag spikes when exploring quickly, and the ability to support longer view distances or faster pregeneration on servers.
Versions: 1.17.1 to 1.21.x (actively developed by ishland, updated recently).
Dependencies: None required (Fabric API recommended).
Tip: Combine C2ME with Lithium and Starlight/ScalableLux for maximum effect. Note: C2ME is still experimental and may cause minor issues with some world-gen mods. Best tested on staging servers before production use.
Memory and loading time optimizations
FerriteCore (MC 1.16.5+ – Client & Server)
Optimizes Minecraft’s memory usage. FerriteCore changes how certain frequently duplicated objects (e.g., block states, models, biome data) are stored to reduce the overall RAM footprint. In modded setups, it’s highly effective at lowering RAM usage. For example, in the All of Fabric 3 pack, heap usage dropped from 1792MB to 984MB with FerriteCore (Hydrogen reached 1335MB in the same test, but it is no longer maintained).
Versions: 1.16.5 to 1.21.5 (kept up to date for all recent versions).
Dependencies: None. Works on both client and server (install on both sides for full benefit). Compatible with nearly everything. (Note: Redundant if you still use Hydrogen on older versions — they cover the same optimization.) Ideal for players with RAM issues or large Fabric modpacks.
Memory Leak Fix (MC 1.14.4 – 1.20.4 – Client & Server)
As the name suggests, this mod patches several memory leaks present in vanilla Minecraft (both client and server). Some vanilla routines fail to release memory properly, which over time leads to growing RAM usage, lag, or crashes (especially during repeated resource loads, dimension changes, etc.). Memory Leak Fix plugs these known leaks.
Versions: 1.14.4 to 1.20.4 (no 1.21 version yet at the time of writing).
Dependencies: None. Install on client and/or server depending on your needs.
Note: The author recommends using it with Lithium and FerriteCore for optimal performance and memory handling. If upgrading to 1.21+, look out for newer versions or alternatives, as vanilla updates may have addressed some leaks.
LazyDFU (MC 1.14 – 1.19.4 – Client & Server)
Speeds up game startup by deferring the initialization of the DataFixerUpper (DFU) system. DFU is used to convert old saves to newer formats, but Minecraft initializes it at every launch even if it’s not needed right away, causing a startup delay. LazyDFU changes this so DFU loads only when required (e.g., when loading an old world).
Versions: 1.14.x to 1.19.4 (as of 1.19.4+, Mojang has improved async DFU handling, reducing LazyDFU’s usefulness — hence no 1.20/1.21 versions).
Dependencies: None. Just drop it into /mods and enjoy faster startup times.
Smooth Boot (MC 1.16.1 – 1.19.x – Client & Server)
Improves Minecraft’s multithreaded loading by preventing CPU spikes during game or chunk loading. Vanilla tends to spawn too many worker threads at once on multi-core CPUs, which can overwhelm the OS scheduler and cause stuttering. Smooth Boot lets you limit and spread thread usage more evenly, resulting in smoother and more stable load times. While initial loading may take slightly longer in seconds, it avoids freezing and improves overall system responsiveness.
Versions: 1.16.1 to 1.19.x (archived; Mojang partly fixed this in 1.19.4).
Dependencies: None (configurable via config file or Mod Menu).
For Minecraft 1.20+: Smooth Boot is no longer updated, but a fork named ThreadTweak now handles thread behavior in 1.20/1.21. It continues the same idea — optimizing load thread scheduling — and is recommended if you're still experiencing thread-related issues on newer versions.
ModernFix (MC 1.16.5+ – Client & Server)
An all-in-one optimization mod that improves multiple performance aspects of modern Minecraft (1.16+). It includes fixes and optimizations for faster startup, world loading, reduced memory usage, and bug patches. ModernFix also includes Mojang fixes backported to older versions, optimizes asset loading, and optionally revamps the 3D model loader for more efficient on-demand loading. Tests on large modpacks like All The Mods 8 (Forge 1.18) show up to 2× faster startup and several GB less RAM used with ModernFix enabled.
Versions: 1.16.5, 1.18.2, 1.19.2, 1.19.4, 1.20.x, 1.21.x (wide support, actively maintained).
Dependencies: None (fully standalone, supports Fabric and Forge).
Note: Most of ModernFix’s gains shine in modded environments, but even near-vanilla installs benefit from faster startup and bug fixes. Fully compatible with other performance mods like Lithium, Sodium, Ferrite, etc.
DashLoader (MC 1.16.5 – 1.20.6 – Client)
Greatly accelerates game and resource loading by caching rendering data. On first launch with DashLoader, the mod lets Minecraft load assets normally (models, textures, etc.) and creates a cache. On subsequent launches, it reloads from this optimized cache instead of reprocessing everything, resulting in significantly faster startup. On large modded instances, this can save minutes.
Versions: 1.16.5 to 1.20.6 (no 1.21 version yet — project is awaiting a new maintainer).
Dependencies: None (but may conflict with some all-in-one mods — DashLoader v3.0 improves this by not caching unsupported mods).
Note: Best suited if you launch the game or switch packs/servers often. The first run will be slower (cache creation), but you’ll see clear benefits after. If it isn’t updated for 1.21+, keep an eye out for forks or alternatives.