ImmediatelyFast
github.com
What it is
ImmediatelyFast is a free, open source Minecraft mod that improves client-side rendering performance in Minecraft: Java Edition. It batches draw calls using a custom buffer and sends data to the GPU more efficiently. Its optimizations cover entities, block entities, particles, text, GUI and HUD, maps, and immediate mode rendering used by other mods. The project supports Fabric, Forge, NeoForge, and Quilt, with compatibility listed for Minecraft versions 1.18.2 through 1.21.x and versions 26.1.x, 26.2, and 26.3. It is designed to work with most mods and modpacks, but names OptiFabric, OptiFine, LunarClient, and LabyMod as incompatibilities. The project says it can improve FPS when the CPU is the bottleneck, with slower CPUs benefiting more than very fast ones. A configuration file in the Minecraft instance’s config folder offers performance or compatibility options. The mod is licensed under LGPL-3.0-or-later, and developers can consult API documentation. The project links to a GitHub issue tracker and Discord server for support.
Spec sheet
- What it does
- ImmediatelyFast is an open-source Minecraft client mod that accelerates immediate-mode rendering.Read 15 Oct 2026 · github.com
- Security
- GitHub reports that the project has no security policy file and no published security advisories.Read 7 Oct 2026 · github.com
- Support
- The project directs users to report issues through its GitHub issue tracker and links to a Discord server.Read 7 Oct 2026 · github.com
- License
- The project is licensed under LGPL-3.0-or-later.Read 7 Oct 2026 · modrinth.com
- API main class
- The documented main class is net.raphimc.immediatelyfast.ImmediatelyFast, which exposes loaded configuration, runtime configuration and mod version.Read 15 Oct 2026 · github.com
- Areas optimized
- It optimizes rendering for entities, block entities, particles, text, GUI/HUD, maps, and immediate mode rendering by other mods.Read 7 Oct 2026 · github.com
- Block-entity rendering
- Block-entity rendering receives targeted optimization.Read 15 Oct 2026 · github.com
- Client-only
- Modrinth marks the supported environment as client-side.Read 15 Oct 2026 · modrinth.com
- Client-side
- The project listing identifies the supported environment as client-side Minecraft: Java Edition.Read 7 Oct 2026 · modrinth.com
- Compatibility
- The project is designed to interfere minimally with other mods and modpacks.Read 15 Oct 2026 · github.com
- Configuration
- Configuration is stored in the Minecraft instance config folder and includes atlas, batching, text lookup and framebuffer options.Read 15 Oct 2026 · github.com
- CurseForge reach
- CurseForge shows 190,454,848 downloads for the project.Read 15 Oct 2026 · curseforge.com
- Developer API
- The API documentation shows Gradle installation through the Modrinth Maven repository.Read 15 Oct 2026 · github.com
- Distribution compatibility
- Modrinth lists Minecraft Java Edition 1.18.2 through 26.3 and Fabric, Forge, NeoForge and Quilt loaders.Read 15 Oct 2026 · modrinth.com
- Documentation depth
- The dedicated API document is only 16 lines and provides dependency coordinates plus the main class.Read 15 Oct 2026 · github.com
- Entity rendering
- Entity rendering is one of the optimized areas.Read 15 Oct 2026 · github.com
- Experimental settings
- Experimental error-checking, resource-pack and sign-buffering settings can cause difficult debugging or graphical problems.Read 15 Oct 2026 · github.com
- GUI and HUD
- GUI and HUD rendering are optimized.Read 15 Oct 2026 · github.com
- Independent benchmark
- Modkeel measured no change beyond run variance on Minecraft 26.3 and 26.2, but recorded gains on older versions including 42% on 1.21.1 with 300 mobs.Read 15 Oct 2026 · modkeel.com
- Integration testing
- Modkeel reports successful tests with Sodium, Iris, Entity Culling, Mod Menu, LambDynamicLights, More Culling and Sodium Extra in specified versions.Read 15 Oct 2026 · modkeel.com
- Known incompatibilities
- The README lists OptiFabric/OptiFine and most closed-source clients such as LunarClient and LabyMod as incompatible.Read 15 Oct 2026 · github.com
- Licence
- The source is licensed under the GNU Lesser General Public License version 3.Read 15 Oct 2026 · github.com
- Limit: macOS regression
- A GitHub issue records a macOS performance regression caused by fast buffer uploads on Apple GPUs; the maintainer added automatic disabling and the reporter confirmed improvement.Read 15 Oct 2026 · github.com
- Limit: not always necessary
- A ModDex reviewer says the mod is less necessary when a setup already has only two to four performance mods.Read 15 Oct 2026 · moddex.gg
- Limit: variable gains
- A ModDex reviewer says the frame-rate boost varies substantially by scenario.Read 15 Oct 2026 · moddex.gg
- Limit: VulkanMod conflict
- A Fabric log identifies ImmediatelyFast and VulkanMod 0.6.7 as incompatible and recommends removing one.Read 15 Oct 2026 · mclo.gs
- Maker profile
- RaphiMC (RK_01) describes himself as a Java reverse engineer, developer, Minecraft mod developer and Minecraft protocol expert.Read 15 Oct 2026 · github.com
- Map rendering
- Map rendering has a targeted optimized implementation.Read 15 Oct 2026 · github.com
- Minecraft versions
- The listing shows compatibility with Minecraft versions 1.18.2 through 1.21.x and versions 26.1.x, 26.2, and 26.3.Read 7 Oct 2026 · modrinth.com
- Mod loaders
- The listing names Fabric, Forge, NeoForge, and Quilt as supported platforms.Read 7 Oct 2026 · modrinth.com
- Modrinth reach
- The Modrinth listing shows 133.9 million downloads and 11.7 thousand followers.Read 15 Oct 2026 · modrinth.com
- Other mods
- The mod also optimizes immediate-mode rendering performed by other mods.Read 15 Oct 2026 · github.com
- Particles
- Particle rendering is optimized.Read 15 Oct 2026 · github.com
- Performance benchmark
- An official test with 1,000 cows reported 16 FPS without the mod and 60 FPS with it, using a Ryzen 5 1600, GTX 1060 and Minecraft 1.19.3.Read 15 Oct 2026 · github.com
- Performance limitation
- The author says gains mainly occur when the CPU is the bottleneck and that slower CPUs benefit more.Read 15 Oct 2026 · github.com
- Performance limits
- The project says it can improve FPS when the CPU is the bottleneck and that slower CPUs benefit more than very fast CPUs.Read 7 Oct 2026 · github.com
- Praise: compatibility
- A ModDex reviewer reports no compatibility issues and says it works alongside other performance mods.Read 15 Oct 2026 · moddex.gg
- Praise: performance
- ModDex reviewers repeatedly praise improved FPS, rendering performance and stability.Read 15 Oct 2026 · moddex.gg
- Rating on ModDex
- 4.7 out of 5 from 3 reviews (5 ratings).Read 15 Oct 2026 · moddex.gg
- Recent release
- Release 1.17.1, dated September 17, 2026, fixed a NeoForge crash.Read 15 Oct 2026 · github.com
- Recent release feature
- Release 1.17.0, dated September 16, 2026, added Minecraft 26.3 support.Read 15 Oct 2026 · github.com
- Rendering method
- It batches draw calls with a custom buffer and uploads data to the GPU more efficiently.Read 15 Oct 2026 · github.com
- Rendering optimizations
- It batches draw calls with a custom buffer implementation and uploads data to the GPU more efficiently.Read 7 Oct 2026 · github.com
- Security documentation
- GitHub reports that the repository has no SECURITY.md policy and no published security advisories.Read 15 Oct 2026 · github.com
- Text rendering
- Text rendering is optimized through both general batching and targeted vanilla changes.Read 15 Oct 2026 · github.com
Plans and prices
ImmediatelyFast Free Open source Minecraft client mod · LGPL-3.0-or-later Read 7 Oct 2026 · github.com
Strong points and limits
Strong points
- Free and open source under LGPL-3.0-or-later
- Supports Fabric, Forge, NeoForge, and Quilt
- Optimizes several rendering areas
- Configuration options for performance or compatibility
- Does not require Sodium
Limits
- Known incompatibilities include OptiFine and LunarClient
- Performance gains depend on CPU bottlenecks
- No dedicated server support
Who it suits
ImmediatelyFast may suit Minecraft: Java Edition players seeking client-side rendering optimization, especially when the CPU is the bottleneck. It also provides API documentation for developers.
Verdict
ImmediatelyFast lists its supported loaders, Minecraft versions, rendering targets, and known incompatibilities. Its stated performance benefit depends on whether the CPU is the limiting factor.
Where Specifiction places it
- Minecraft Performance Mods#1 of 248.6