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FleroviumMinecraft mod for 1.21.1

Greatly improve your fps with virtually no side-effects on graphics quality

client onlynewest supported release 1.21.1Optimization
Latest version
1.2.0
Minecraft
1.20.1 to 1.21.1
Java
Java 21+
Loaders
Forge, NeoForge
Licence
LGPL-3.0-only
Downloads
4.8M
Updated
1 mo ago
Available on
Modrinth

Minecraft versions

Every version Flerovium declares support for, newest first, with the Java runtime that version needs.

Other mods
MinecraftThroughJavaEvidenceReleased
1.21.1Forge, NeoForge21+declared8 Aug 2024
1.20.1Forge, NeoForge17+declared12 Jun 2023

Download

From Flerovium’s own host. Nothing is re-hosted here.

Browse 35 indexed releases

Most recently published release

1.2.0alpha26 Sept 2026

flerovium-neoforge-1.21.1-1.2.0-all.jar · 0.2 MB · for 1.21.1 · NeoForge

Download this release
b19e348d01ab…
Older versions24
  • 1.1.312 Sept 20261.21.10.2 MB037fe4e6f601…Get
  • 1.1.214 Jul 20261.21.10.2 MB24.9k downloads6301ea699176…Get
  • 1.2.1920 Jun 20261.20.10.2 MB281.8k downloadsa137aed55fc3…Get
  • 1.1.120 Jun 20261.21.10.2 MB32.7k downloads327449811b11…Get
  • 1.1.016 Jun 20261.21.10.2 MB4.3k downloadsaca9cedc692c…Get
  • 1.0.1819 Apr 20261.21.10.2 MB456.1k downloadsee04af8b6786…Get
  • 1.2.186 Feb 20261.20.10.2 MB754.7k downloadsfeabbd89712a…Get
  • 1.2.1726 Jan 20261.20.10.2 MB29.6k downloads54872413f951…Get
  • 1.0.1721 Dec 20251.21.10.2 MB121.1k downloadsa6c7a79bc2cd…Get
  • 1.0.1617 Dec 20251.21.10.2 MB4.0k downloads0af305aee874…Get
  • 1.2.165 Oct 20251.20.10.2 MB821.8k downloadsf1807d021724…Get
  • 1.0.155 Oct 20251.21.10.2 MB63.4k downloadsd6911552ac08…Get
  • 1.0.1417 Sept 20251.21.10.2 MB24.2k downloadsf11f2a560ca1…Get
  • 1.0.1316 Sept 20251.21.10.2 MB261 downloadse38b2d59efc4…Get
  • 1.0.126 Sept 20251.21.10.2 MB6.9k downloadsf23be8d849d9…Get
  • 1.0.112 Sept 20251.21.10.2 MB3.1k downloads644ae6b49dad…Get
  • 1.0.1028 Jul 20251.21.10.1 MB39.5k downloadseee3195e1bad…Get
  • 1.0.926 Jul 20251.21.10.1 MB2.4k downloads5a7e16f2df12…Get
  • 1.0.720 Jul 20251.21.10.1 MB5.0k downloads89ef3e85520a…Get
  • 1.2.1520 Jul 20251.20.10.2 MB408.4k downloadsdd464cc3c16d…Get
  • 1.2.1429 May 20251.20.10.2 MB222.9k downloadsb209dc5500bf…Get
  • 1.0.619 May 20251.21.10.1 MB44.4k downloadsbf6d68f5e22c…Get
  • 1.2.1313 May 20251.20.10.2 MB45.7k downloadsbb101a2c55b5…Get
  • 1.0.512 May 20251.21.10.1 MB3.0k downloadsb21e294157ba…Get

Frequently asked

Does Flerovium work on Minecraft 1.21.1?

Yes. 1.21.1 is the newest Minecraft version Flerovium declares support for, and the claim comes from the author's own release metadata rather than from a compatibility list somebody maintains by hand.

Which Minecraft versions does Flerovium support?

Everything the author has declared, from 1.20.1 up to 1.21.1. The full list is in the table above, with the Java runtime each version needs next to it.

Do I need to install Flerovium on the client or the server?

The client only. There is nothing to install on the server side. That is the author's declared design, not a guarantee for every server: one running anti-cheat or missing a counterpart mod can still object.

Which platform or loader does Flerovium support?

Forge, NeoForge. A build for one platform or loader will not necessarily load on another, so this is the first thing to check before the Minecraft version.

Which Java version do I need for Flerovium?

Among the supported Minecraft releases above, the highest recorded requirement is Java 21 or newer. Use the requirement for the exact Minecraft version you run; previews and snapshots may differ.

What licence is Flerovium under?

LGPL-3.0-only, as stated by the author on the platform we synced it from. Check the project's own page before redistributing or bundling it.

How do I install Flerovium?

Install the matching loader first, then put the downloaded file in your mods folder and start the game. The loader, the mod and Minecraft all have to be on the same version, which is the usual reason a mod does not appear in game.

Where do I download Flerovium safely?

Start with the author's page on Modrinth, which is where the data here is synced from. MCReference does not host or repackage files. When available, recorded download links go to the source for that release; verify the publisher, filename and any available checksum before running it.

Works on the same versions

Ordered by how much of the recent Minecraft version coverage overlaps, not by popularity.

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Details from Modrinth, where the author last updated it on 26 Sept 2026. We do not host files or republish descriptions. Available download links point to the author’s own release.

Is this information wrong or missing something? .