Menu

mod

HammerLibMinecraft mod for 1.21.4

Utility mod that contains really useful code for quite a few mods.

client and servernewest supported release 1.21.4Library
Latest version
21.0.17
Minecraft
1.10.2 to 1.21.4
Java
Java 21+
Loaders
NeoForge, Forge
Licence
LicenseRef-All-Rights-Reserved
Downloads
858.4k
Updated
1 mo ago
Available on
Modrinth
Space NodeOur hosting

Host HammerLib servers

One click and HammerLib is installed with the right loader, on hardware built for it.

  • 1.21.4
  • NeoForge
  • Forge
  • One click mod install
  • Loader matched for you
  • Ryzen CPUs
  • NVMe SSD
Deploy a serverFrom €0.90 per GB

Minecraft versions

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

Other mods
MinecraftThroughJavaEvidenceReleased
1.21.4NeoForge, Forge21+declared3 Dec 2024
1.21.1NeoForge, Forge21+declared8 Aug 2024
1.21Forge, NeoForge21+declared13 Jun 2024
1.20.6NeoForge, Forge21+declared29 Apr 2024
1.20.5NeoForge, Forge21+declared23 Apr 2024
1.20.4NeoForge, Forge17+declared7 Dec 2023
1.20.3NeoForge, Forge17+declared4 Dec 2023
1.20.2NeoForge, Forge17+declared20 Sept 2023
1.20.1NeoForge, Forge17+declared12 Jun 2023
1.20NeoForge, Forge17+declared2 Jun 2023
1.19.3Forge, NeoForge17+declared7 Dec 2022
1.19.2NeoForge, Forge17+declared5 Aug 2022
1.18.2NeoForge, Forge17+declared28 Feb 2022
1.18.1Forge, NeoForge17+declared10 Dec 2021
1.16.5NeoForge, Forge8+declared14 Jan 2021
1.16.3NeoForge, Forge8+declared10 Sept 2020
1.15.2NeoForge, Forge8+declared17 Jan 2020
1.13.2NeoForge, Forge8+declared22 Oct 2018
1.12.2NeoForge, Forge8+declared18 Sept 2017
1.11.2Forge, NeoForge8+declared21 Dec 2016
1.11NeoForge, Forge8+declared14 Nov 2016
1.10.2Forge, NeoForge8+declared23 Jun 2016

Download

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

Browse 62 indexed releases

For Minecraft 1.21.4

Choose the loader you use before downloading.

  • NeoForge

    21.4.5 · 5 Mar 2025 · HammerLib-1.21.4-21.4.5.jar

    Get NeoForge

Most recently published release

21.0.17release25 Sept 2026

HammerLib-1.21-21.0.17.jar · 2.3 MB · for 1.21.1, 1.21 · NeoForge

Download this release
d5de4cecae6f…
Older versions24
  • 21.0.1615 Sept 20261.21.1, 1.212.3 MB8d5478756582…Get
  • 21.0.159 Sept 20261.21.1, 1.212.1 MBc5c6f54ddd42…Get
  • 12.2.6614 Jul 20261.12.22.5 MB4.2k downloadsd65931ba7ea0…Get
  • 12.2.6527 Jun 20261.12.22.5 MB3.7k downloads0a9e7ae3e3d6…Get
  • 12.2.6313 Jun 20261.12.22.5 MB2.9k downloads43eca220d144…Get
  • 12.2.627 Jun 20261.12.22.5 MB1.1k downloads70d5090bb6f3…Get
  • 12.2.613 Jun 20261.12.22.5 MB1.1k downloadsca45eb430d47…Get
  • 12.2.601 Jun 20261.12.22.4 MB282 downloads17280f14daaf…Get
  • 12.2.5931 May 20261.12.22.4 MB235 downloads842c63925069…Get
  • 12.2.5826 Mar 20251.12.22.5 MB130.8k downloadsdc1eeed9bb23…Get
  • 20.1.5023 Mar 20251.20.12.3 MB217.1k downloads85f1c4166eb9…Choose file on publisher ↗
  • 21.4.55 Mar 20251.21.42.4 MB1.8k downloads4c345ce88fab…Get
  • 21.4.45 Mar 20251.21.42.4 MB80 downloads619058bdff0b…Get
  • 21.4.35 Mar 20251.21.42.4 MB65 downloadseed405acd73b…Get
  • 21.4.24 Mar 20251.21.42.4 MB56 downloads2f580918d5b1…Get
  • 21.4.14 Mar 20251.21.42.2 MB74 downloads283e74038f63…Get
  • 20.1.4818 Jan 20251.20.12.3 MB58.1k downloadse330d30c7bcc…Choose file on publisher ↗
  • 20.1.4718 Jan 20251.20.12.3 MB145 downloads1d43eb756de7…Get
  • 20.1.4618 Jan 20251.20.12.3 MB939 downloads663a9de79b61…Get
  • 20.1.4517 Jan 20251.20.12.3 MB109 downloads27453c0d835e…Get
  • 20.1.4413 Jan 20251.20.12.3 MB354 downloads53dbbf538a3f…Get
  • 20.1.4313 Jan 20251.20.12.3 MB378 downloads7a3230172897…Get
  • 20.1.416 Jan 20251.20.12.3 MB5.4k downloads6ba7985e9981…Get
  • 20.1.394 Jan 20251.20.12.3 MB253 downloads9d23aacd7247…Get

Frequently asked

Does HammerLib work on Minecraft 1.21.4?

Yes. 1.21.4 is the newest Minecraft version HammerLib 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 HammerLib support?

Everything the author has declared, from 1.10.2 up to 1.21.4. The full list is in the table above, with the Java runtime each version needs next to it.

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

Both. Every player needs it installed and so does the server, so anyone joining without it will be refused.

Which platform or loader does HammerLib support?

NeoForge, Forge. 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 HammerLib?

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 HammerLib under?

LicenseRef-All-Rights-Reserved, 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 HammerLib?

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 HammerLib 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.

GeckoLibA 3D animation library for entities, blocks, items, armor, and more!Cloth Config API (Fabric/Forge/NeoForge)Config Screen API for MinecraftJourneyMapReal-time map used for mapping in-game or your browser as you explore.Architectury APIAn intermediary api aimed to ease developing multiplatform mods.Jade 🔍Shows information about what you are looking at. (Hwyla/WAILA fork for Minecraft 1.16+)Collective🎓 Collective is a shared library with common code for all of Serilum's mods.

Used by

2 projects list HammerLib as a required dependency.

HammerAnimationsBrings Bedrock model and animation as a compact and easy-to-use API layer with hotswapping.CloudflaredPlay with your friends over CloudFlare.

Details from Modrinth, where the author last updated it on 25 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? .