1.21.5 Pre-release 2 — release journal

What 1.21.5-pre2 changed for data packs, measured against 1.21.5-pre1, the build before it. Released 2025-03-12; development build — not a release.

⚠ Format moved, no registry changed

The data pack format moved but no registry entry changed. That is not a no-op: the change is in file schemas — field shapes and required keys — which a registry diff cannot see. Read the article's technical sections below.

Formats

1.21.5-pre11.21.5-pre2
Data pack format70.071.0 moved
Resource pack format55.055.0
Data version43204321

Registries

No registry gained, lost or changed an entry.

The official notes

Read the 1.21.5 Pre-release 2 article on minecraft.net.

The article has no technical-changes section — it lists bug fixes only, or predates that heading.

Minecraft Wiki page for 1.21.5-pre2.

In the journal

← 1.21.5-pre1 · All builds · 1.21.5-pre3 →

Sources