Minecraft 26.3 Snapshot 4 Changes for Server Hosts

Mojang has released a testing build that upgrades internal scripting and client display libraries. The update for minecraft 26.3 snapshot 4 raises the data pack specification to version 111.0 and adjusts how commands, item data, and environment mob spawning interact on servers.

Hosts testing future world configurations can inspect the live landscape on our Minecraft Server List or evaluate dedicated Minecraft 26.3 servers as release snapshots evolve.

Backend display and input updates

Mojang has migrated the desktop client windowing and input integration away from GLFW over to SDL3. This structural change reshapes fullscreen handling and input management across operating systems.

Display modes and window management

Borderless Fullscreen now serves as the default fullscreen setting. Players can alternate between Borderless and Exclusive modes without having to reboot the game client. However, Exclusive Fullscreen mode is no longer supported on macOS. Additionally, on Linux configurations, native Wayland is selected and preferred automatically whenever present. The smallest window dimensions supported by the client are now fixed at 320 by 240 pixels.

Input changes and known crashes

In-game mouse movements now continuously utilise relative mouse tracking, leading to the removal of the raw input option. Physical keyboard positioning via SDL scancodes replaces layout-specific key binding codes, while text editing shortcuts depend on SDL keycodes. Mac users holding a key will see the operating system's native accent and candidate selector.

Mojang noted two known issues with Exclusive Fullscreen: selecting it on Wayland triggers an immediate crash, and running it on Windows can also crash the client, particularly across setups using multiple monitors.

Data Pack 111.0 and world mechanics

Data packs update to format 111.0, while resource packs move to version 92.0. The update alters click behaviour and teleports across server worlds.

Sign commands and teleport tags

Signs and hanging signs no longer run click events or attached commands automatically when interacted with. Pack authors must adjust setups that relied on default sign triggers for menu routing or permission triggers. For command routing, /spreadplayers now evaluates target destinations against the #entities_can_teleport_to block tag to decide whether an arrival point is safe.

Environment attributes and mob spawning

Custom dimensions and biomes now support minecraft:gameplay/natural_mob_spawns. This environment attribute lets creators configure category mappings with weighted spawn lists, quantity providers, and energy budget costs that dictate entity density. A related attribute, minecraft:gameplay/creature_world_gen_spawn_probability, establishes a decimal float chance (defaulting to 0.1) that determines whether creature generation passes execute during world creation. Ambient particle definitions under minecraft:visual/ambient_particles also gain keyframe interpolation and an append modifier that joins layers together rather than replacing them.

Item components and registry references

Custom loot tables and data components receive extensive format expansions in this release.

Expanded registry lookups

Dedicated registries—including item modifiers, predicates, number providers, recipes, slot sources, advancements, and loot tables—now accept direct inline definitions or tag identifiers prefixed with #. Previous standalone reference types built specifically for predicates, item modifiers, and slot sources have been declared obsolete and removed.

New data components

Server administrators and map makers have access to several item components:

• minecraft:cooking_fuel: Configures burn durations and smelting rates using elements from the number provider registry.
• minecraft:brewing_fuel: Sets usage counts and speed multipliers for brewing stands, fully superseding the legacy #brewing_fuel item tag which has been removed.
• minecraft:sign_text_front and minecraft:sign_text_back: Define tooltip previews and text on sign items using structured message lists.
• minecraft:villager_food: Dictates villager consumption and hunger restoration values, working alongside the #villager_picks_up tag.
• minecraft:mob_visibility: Scales entity detection distance between 0.0 (limiting vision to two blocks) and 10.0 (a tenfold expansion).
• minecraft:cushion/color and minecraft:waxed: Act as placement markers and state tags.

Earlier iterations of these systems can be contrasted with later builds, such as how Minecraft 26.3 Pre-Release 1 Splits Number Registries across subsequent pack updates.

Server administrative impact

Deploying this snapshot breaks older data packs immediately due to the removal of dedicated predicate and slot reference types, along with the deletion of the #brewing_fuel item tag. Any automated sign menus running command clicks must be rewritten or handled via external server logic, as signs no longer trigger embedded commands by default. Survival mechanics also require verification if custom spawning datapacks are active, as biome spawn logic now routes through environment attributes.

Player facing changes

Players joining an updated world will notice altered creative menus. Mineral items appear arranged with non-tiered crafting components first, refined ingots second, and finished gear materials last, while natural blocks progress systematically from the Overworld to the Nether and the End. Spectators can now travel through portals to teleport between dimensions. In survival play, armadillos stop attempting to roll into protective shells when submerged in liquids.