Released 2024-08-08
Minecraft 1.21.1: Java 21
1.21.1 is the stable point of the 1.21 line and the version most current modded packs target. Java 21, NeoForge or Fabric for mods, Paper or Purpur for plugins.
Java version required
21or newer
Older Java will refuse to start. Much newer Java usually works, but the server software is what decides that, not Minecraft.
Availability
Paper is available for 1.21.1
It accepts Bukkit / Spigot / Paper plugins.
Will what I downloaded work?
Mods and plugins are different things that both arrive as a .jar file. Putting the wrong one in usually produces no error at all — the server starts, and the content simply is not there.
running on Paper
No. Forge produces mods and Paper runs plugins — they are different systems that happen to share a file extension. Nothing will load, and nothing will warn you.
What to watch for on this version
Forge still publishes for 1.21, but the modding community has effectively completed its move to NeoForge on this line — searching for a Forge build of a 1.21 mod will often turn up nothing, and that absence is the ecosystem rather than a gap in your search.
Where this sits in the Java timeline
- Java 81.7 through 1.16.5
- Java 161.17 and 1.17.1
- Java 171.18 through 1.20.4
- Java 211.20.5 and everything after