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mod

Fast NBTMinecraft mod for 1.21.1

Speed up all kinds of NBT operations and improve game performance

newest supported release 1.21.1Performance
Latest version
fastnbt-1.19-26.9.1-forge.jar
Minecraft
1.18.2 to 1.21.1
Java
Java 21+
Loaders
Forge, NeoForge
Licence
not stated
Downloads
987.4k
Updated
8 d ago
Available on
CurseForge

Minecraft versions

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

Other mods
MinecraftThroughJavaEvidenceReleased
1.21.1Forge, NeoForge21+declared8 Aug 2024
1.21Forge, NeoForge21+declared13 Jun 2024
1.20.1NeoForge, Forge17+declared12 Jun 2023
1.20NeoForge, Forge17+declared2 Jun 2023
1.19.2NeoForge, Forge17+declared5 Aug 2022
1.18.2Forge, NeoForge17+declared28 Feb 2022

Download

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

For Minecraft 1.21.1

Choose the loader you use before downloading.

  • NeoForge

    fastnbt-1.21.1-26.9.1-neoforge.jar · 19 Sept 2026 · fastnbt-1.21.1-26.9.1-neoforge.jar

    Get NeoForge

Most recently published release

fastnbt-1.19-26.9.1-forge.jarrelease30 Oct 2026

fastnbt-1.19-26.9.1-forge.jar · 23 KB · for 1.19.2 · Forge

Download this release
632db46e9329…
Older versions4
  • fastnbt-1.18-26.9.1-forge.jar30 Oct 20261.18.223 KBa0acd422aa3f…Get
  • fastnbt-1.21.1-26.9.1-neoforge.jar19 Sept 20261.21.1, 1.2123 KBb49b12d9d006…Get
  • fastnbt-1.20-26.9.1-forge.jar19 Sept 20261.20.1, 1.2023 KBa03c9413abbe…Get
  • fastnbt-1.20.1-1.3-forge.jar29 Mar 20261.20.110 KB51a7bd788b3c…Get

Frequently asked

Does Fast NBT work on Minecraft 1.21.1?

Yes. 1.21.1 is the newest Minecraft version Fast NBT 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 Fast NBT support?

Everything the author has declared, from 1.18.2 up to 1.21.1. The full list is in the table above, with the Java runtime each version needs next to it.

Which platform or loader does Fast NBT 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 Fast NBT?

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.

How do I install Fast NBT?

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 Fast NBT safely?

Start with the author's page on CurseForge, 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 CurseForge, where the author last updated it on 30 Oct 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? .