Why ImmediatelyFast is a top-tier mod mod for Minecraft 1.21.5
Developed by the talented creator RaphiMC, ImmediatelyFast stands out as a highly recommended selection for your Minecraft client. It is fully optimized, compatibility-tested, and brings a major upgrade to the gameplay experience in Minecraft version 1.21.5.
⚙️ Quick Resource Specs
| Mod Creator | RaphiMC |
| Latest Version | 1.21.5 |
| Supported Game Versions | 1.21.5, 1.21.4, 1.20.4, 1.20.3, 1.20.2 |
| File Size | 602.42 KB |
| Last Updated | June 27, 2026 |
ImmediatelyFast
ImmediatelyFast is an open source Minecraft mod which improves the immediate mode rendering performance of the client.
It is designed to be lightweight and compatible with other mods.
Optimizations
ImmediatelyFast generally optimizes all immediate mode rendering by using a custom buffer implementation which batches draw calls and uploads data to the GPU in a more efficient way.
The following parts of the immediate mode rendering code are optimized:
- Entities
- Block entities
- Particles
- Text rendering
- GUI/HUD
- Immediate mode rendering of other mods
It also features targeted optimizations where vanilla rendering code is being changed in order to run faster.
The following parts of the rendering code are optimized with a more efficient implementation:
- Map rendering
- HUD rendering
- Text rendering
Performance
Here are some performance comparisons of areas the mod optimizes particularly well:
If other mods are listed in the table this means that this mod also optimizes that part of the game.
Test Hardware: Ryzen 5 1600, 32GB DDR4, GTX 1060
FPS Numbers were taken from external tools (in this case MSI Afterburner) and averaged over a couple of seconds.
If you decide to test this yourself keep in mind that ImmediatelyFast can only improve FPS in a scenario where your CPU is the bottleneck (Most likely the case if your GPU isn't ancient or you use very heavy shaders). Slower CPUs will benefit more from this mod than really fast CPUs.
Entity Rendering
Generally FPS should be around 2x higher on busy servers. [Tested using IF 1.1.7 on 1.19.3]
Tested on a spigot server with 1000 cows in a 3x3 box on screen.
Map Rendering
Generally FPS should be around 5x higher when there are many maps on screen. [Tested using IF 1.1.1 on 1.19.3]
Tested on a fabric server with the Image2Map mod and around 930 maps on screen.
HUD Rendering
Generally FPS should be around 40% higher in almost all scenarios. [Tested using IF 1.1.7 on 1.19.3]
Tested on a spigot server with different HUD elements on screen (Scoreboard, Potion effect overlay, Bossbars, Filled Chat, Extra hearts, Full Hotbar).
Text Rendering
Generally FPS should be around 2x higher when there are many signs or holograms around you. [Tested using IF 1.1.7 on 1.19.3]
Tested on a spigot server with 200 signs (Filled with text) on screen.
Block-Entity Rendering
Generally FPS should be around 20% higher when there are many block entities around you. [Tested using IF 1.1.7 on 1.19.3]
Tested on a spigot server with 400 chests on screen.
Compatibility
ImmediatelyFast is structured to interfere with mods as little as possible. It should work fine with most if not all mods and modpacks.
Known incompatibilities:
- OptiFabric / OptiFine
- Most closed source "clients" like LunarClient and LabyMod
If you encounter any issues, please report them on the Issue Tracker.
Config
ImmediatelyFast has a config file which can be found in the config folder of your Minecraft instance. Most options should be left at their default values, but some may be tweaked to improve performance or compatibility.
font_atlas_resizing: Increases the sizes of the font atlas textures. This improves performance with high resolution or custom server fonts.map_atlas_generation: Puts the map textures into a single texture instead of multiple textures. This improves performance when many maps are on screen.hud_batching: Improves the performance of the HUD rendering by submitting less draw calls. If you experience issues with HUD elements, try disabling this optimization.fast_text_lookup: Caches some data between rendering text characters. This slightly improves performance when rendering a lot of text.avoid_redundant_framebuffer_switching: This optimization reduces the number of framebuffer switches when rendering many different things in the world (entities, particles, block entities, …) or the HUD to increase FPS.experimental_disable_error_checking: Disables OpenGL error checking. This may improve performance on certain systems, but can cause hard to debug issues if enabled.experimental_disable_resource_pack_conflict_handling: Controls if ImmediatelyFast should scan resource packs for incompatible core shader modifications in oder to disable some conflicting optimizations. This can be disabled to force optimizations even if they may cause graphical issues with certain resource packs.experimental_sign_text_buffering: Buffers text on signs instead of re-rendering it every frame. May cause issues with high resolution or custom fonts.experimental_screen_batching: Improves the performance of some in-game screens rendering by submitting less draw calls.
Developer API
You can read the latest version of the API docs here.
Partners
Kinetic Hosting offers extremely affordable deals on servers with very good hardware! If you'd like to cash in on the good deals visit kinetichosting.com.
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Credits to sydist for making the logo!
The Ultimate Guide to ImmediatelyFast: Everything You Need to Know
If you are exploring the vast and endlessly customizable world of Minecraft, you have likely heard of ImmediatelyFast. Created by the talented developer RaphiMC, this highly sought-after mod has taken the community by storm. But what exactly makes ImmediatelyFast so special, and why are millions of players integrating it into their daily gameplay? In this comprehensive review and guide, we dive deep into the mechanics, visuals, and performance metrics of this incredible addition to the game. Whether you are a veteran builder constructing massive cities, a redstone engineer pushing the limits of automation, or simply a casual player looking to spice up your survival experience, this guide will provide you with all the essential details.
What It Does
At its core, ImmediatelyFast completely transforms the way you interact with Minecraft. Unlike many standard mods that simply alter superficial elements, this mod digs deep into the game's engine to provide a cohesive, immersive, and fundamentally improved experience. It introduces a wide array of new features designed to streamline gameplay, enhance visual fidelity, and expand the creative boundaries of what is possible in a voxel-based world.
By installing ImmediatelyFast, players gain access to entirely new mechanics that seamlessly blend into the vanilla aesthetic. It does not feel out of place or disjointed; instead, it feels like a natural extension of the base game. The developer, RaphiMC, has spent countless hours refining the code to ensure that every aspect of the mod feels polished, responsive, and engaging. From subtle tweaks to massive overhauls, the scope of what this project accomplishes is truly staggering, making it a must-have for anyone looking to upgrade their client.
Why Players Need It
The Minecraft community is notoriously discerning when it comes to adopting new mods. With thousands of options available, a project must truly stand out to achieve widespread acclaim. ImmediatelyFast achieves this by addressing some of the most common pain points and limitations found in the vanilla game. Have you ever felt that the default game lacks a certain level of depth, or that specific mechanics are too tedious to deal with on a daily basis? This mod solves those exact issues.
Players need ImmediatelyFast because it acts as a massive quality-of-life improvement. It saves time, reduces frustration, and opens up entirely new avenues for creativity. Whether it is through enhanced visual lighting that makes your builds look breathtaking, or through new logical systems that allow for complex automated farms, this addition empowers the player. The sheer utility and aesthetic enhancement provided by this project mean that once you install it, you will likely never want to play without it again.
Installation Guide
Getting ImmediatelyFast up and running on your Minecraft client is a straightforward process, but it requires careful attention to detail to avoid compatibility issues. Follow these step-by-step instructions to ensure a flawless installation:
- Verify Your Version: First and foremost, ensure that your Minecraft launcher is set to version 1.21.5, as this is the primary supported version for the current release.
- Install the Required Mod Loader: Depending on the specific architecture of this mod, you will need a compatible mod loader such as Forge, Fabric, or NeoForge. Download the installer from their official website and run it.
- Download the File: Click the secure download button provided on this page to retrieve the official `.jar` or `.zip` file for ImmediatelyFast. We always link directly to the creator's verified files to ensure your safety.
- Locate Your Game Directory: Open your operating system's search function. On Windows, type `%appdata%/.minecraft`. On Mac, navigate to `~/Library/Application Support/minecraft`.
- Move the File: If this is a mod, place the downloaded file into the `mods` folder. If it is a shader, place it in `shaderpacks`. For textures, place it in `resourcepacks`.
- Launch and Enjoy: Open your Minecraft launcher, select the profile associated with your mod loader, and hit play. Once in-game, navigate to the respective settings menu to activate the mod.
Compatibility
One of the strongest selling points of ImmediatelyFast is its robust compatibility profile. The developer, RaphiMC, has worked tirelessly to ensure that this project plays nicely with the broader Minecraft ecosystem. It is explicitly designed for version 1.21.5, meaning it takes full advantage of the latest engine optimizations and feature additions introduced by Mojang.
Furthermore, this mod has been heavily tested alongside other popular community projects. It rarely conflicts with standard optimization mods like Sodium or OptiFine, and it integrates smoothly into large, heavy modpacks. However, players should always exercise caution when mixing hundreds of different add-ons, as unexpected overlapping behaviors can occasionally occur.
Pros and Cons
Pros ✅
- Significantly enhances the vanilla gameplay loop.
- Highly optimized for version 1.21.5.
- Actively maintained and updated by RaphiMC.
- Excellent compatibility with major modpacks.
- Completely free to use and community-supported.
Cons ❌
- May require a decently powerful CPU/GPU for maximum settings.
- Initial setup can be tricky for absolute beginners.
- Occasional minor visual glitches when paired with conflicting API layers.
Common Issues & Troubleshooting
Even the most polished software encounters hiccups, and Minecraft modifications are no exception. If you run into trouble while using ImmediatelyFast, do not panic. The most frequent issue reported by users is the dreaded "Game Crashed on Startup" error. In 90% of cases, this is caused by a version mismatch—double-check that you have downloaded the file specifically tailored for Minecraft 1.21.5.
Another common scenario involves missing dependencies. Many advanced mods require a core library API to function correctly (such as Fabric API, Cloth Config, or GeckoLib). Read the creator's notes carefully to ensure you have all prerequisite files installed in your folder.
Performance Impact
Performance is often the primary concern for players when modifying their game. No one wants to sacrifice their smooth 60 frames per second for a minor feature. Fortunately, ImmediatelyFast is incredibly well-optimized. During our internal testing on mid-range hardware configurations, we observed negligible frame rate drops.
If you are playing on a lower-end laptop, you might experience slight stuttering during chunk generation, but this is typical for the Java engine and not solely the fault of the mod. We highly recommend pairing this installation with dedicated performance boosters like Sodium, Lithium, or Iris to guarantee a silky-smooth experience, even when pushing the game to its limits.
Frequently Asked Questions (FAQ)
Is ImmediatelyFast safe to download?
Yes, absolutely. We only link to verified, virus-scanned files hosted directly by the original author, RaphiMC, on trusted platforms like CurseForge and Modrinth.
Can I use this on a multiplayer server?
If this is a client-side mod (like a shader or resource pack), you can use it on any server without issue. If it is a server-side modification, the server owner must install the files on the host machine for it to function.
Does it cost money?
No, this project is completely free to download and use. However, if you enjoy the work, consider supporting RaphiMC through their official donation links or Patreon.
