Minecraft 25w09a Update - What's New
Fallen trees came to Java Edition to match Bedrock, in oak, birch, jungle and spruce, and firefly bushes started to generate in mangrove swamps and, rarely, in badlands.
Overview
Minecraft 25w09a is a weekly development snapshot for Minecraft: Java Edition, published on February 26, 2025. Snapshots are Mojang's weekly previews of in-progress features (development week 9 of 2025), shipped early so the community can test and report problems before anything is finalized. This one logs 8 changes you can try in a throwaway test world.
The work in this update spans new features, changes, and technical. On the new features side it brings Fallen trees in oak, birch, jungle and spruce, some with mushrooms or vines on them and Birch fallen trees come in a short and a long version.
This build is part of the development cycle leading to 1.21.5 (the Spring to Life drop). Treat it as a preview rather than a destination: features can change, be renamed, or be cut entirely before they reach the stable release, so it is meant for testing and feedback, not for your main world or a live server.
Changes
#New Features(3)
- Fallen trees in oak, birch, jungle and spruce, some with mushrooms or vines on them
- Birch fallen trees come in a short and a long version
- They generate wherever the standing tree grows, except meadows, bamboo jungles, rivers and groves
#Changes(2)
- Leaf litter can be replaced by other blocks
- Firefly bushes generate near water in mangrove swamps and, very rarely, in badlands
#Technical(3)
- Data pack version 69
- The data command can create and change lists with mixed types
- Many entity fields got sensible default values when they are left out
Server Admin Migration Guide
- Snapshot only, not for a live server: keep production on the current release
- Summon commands that leave out fields such as Fuse or Duration now get default values
Known Issues
- Development snapshot, features can still change before 1.21.5
What This Means
For players
Snapshots are opt-in through the official launcher. Always make a copy of any world before opening it in 25w09a, because development builds can corrupt saves and there is no guarantee the world will open in a later version. Use a fresh test world to try the new content safely.
For server admins
Do not run 25w09a on a public server. Snapshots are unsupported by server software and most plugins. Spin up a private staging instance, confirm your plugins load, and report regressions while there is still time to fix them before release.
Background & Context
- Snapshots ship roughly once a week during active development and are enabled through the "Latest snapshot" toggle in the official launcher.
- The content here was being developed toward 1.21.5 (the Spring to Life drop); individual features may have been adjusted, renamed, or removed before that version shipped.
- Always keep a backup of important worlds before changing versions; the Astroworld versions database tracks client and server compatibility for 25w09a.
Frequently Asked Questions
When was Minecraft 25w09a released?
Minecraft 25w09a was released on February 26, 2025 as a weekly development snapshot for Minecraft: Java Edition.
What is new in 25w09a?
Fallen trees came to Java Edition to match Bedrock, in oak, birch, jungle and spruce, and firefly bushes started to generate in mangrove swamps and, rarely, in badlands. Notable entries include: Fallen trees in oak, birch, jungle and spruce, some with mushrooms or vines on them; Birch fallen trees come in a short and a long version; They generate wherever the standing tree grows, except meadows, bamboo jungles, rivers and groves. In total it documents 8 changes across 3 categories.
Should I use 25w09a on my main world?
No. 25w09a is a weekly development snapshot meant for testing. Keep your main world on the latest stable release and only open a backup copy in a separate test world to try the new content.
Can I run 25w09a on a Minecraft server?
It is not recommended for a public server. Snapshot only, not for a live server: keep production on the current release. Use a private staging instance to test plugins and mods, not to host players.
Which Minecraft version is 25w09a a preview of?
25w09a is part of the development cycle for 1.21.5 (the Spring to Life drop). Features shown here are still in progress and may change before the final release.
Are there known issues in 25w09a?
Yes. Documented issues for this build include: Development snapshot, features can still change before 1.21.5. Development builds are expected to have rough edges that get fixed before release.
Looking for version compatibility info?
Check client and server version details on our versions database.