Minecraft Block Entity Data Format

Block Entity Data Format

Block entities extend block states with extra behavior and data. Java Edition only.

Common Tags

Every block entity shares:

• x, y, z (required) — block coordinates.
• id (required) — block entity type namespace ID.
• components — data components copied from the item used to place the block entity (only components the item carries that are not handled by inheritance serialization). See the data-component skill, "Block entities" section.

Block Entity Data List

Per-block-entity tags (each includes the common tags above). See the Minecraft Wiki "Block entity format" page for complete details; * marks required tags.

• Banner — CustomName (text component; → component custom_name), patterns (default empty; list of {color, pattern} banner patterns; → banner_patterns).
• Barrel — container: CustomName, lock (item predicate), Items (27 slots; → container), LootTable + LootTableSeed (→ container_loot; removed after loot generates).
• Beacon — Levels (pyramid level, not modifiable via /data), lock, CustomName, primary_effect, secondary_effect (effect IDs).
• Bed — no extra tags.
• Beehive — bees (list of {entity_data (partial bee NBT; only #beehive_inhabitors entities load; many movement tags are not saved), min_ticks_in_hive, ticks_in_hive, flower_pos}; → bees component).
• Bell — no extra tags.
• Blast Furnace / Furnace / Smoker — smelting state: CustomName, lock, Items (slot 0 input, 1 fuel, 2 result), cooking_time_spent, cooking_total_time, lit_time_remaining, lit_total_time, speed_multiplier (default 1.0), RecipesUsed (recipe IDs → count).
• Brewing Stand — BrewTime (remaining, −1/tick), Fuel (energy; refills to 20 with blaze powder when <0), Items (slots 0–2 potions, 3 ingredient, 4 fuel), CustomName, lock.
• Suspicious Sand / Suspicious Gravel — hit_direction (0–5 = down/up/north/south/west/east; load//data only), item (held item), LootTable + LootTableSeed.
• Calibrated Sculk Sensor / Sculk Sensor — last_vibration_frequency (analog output), listener (vibration listener data).
• Campfire — CookingTimes, CookingTotalTimes (4-element int arrays), Items (4 slots).
• Chest / Trapped Chest / Ender Chest / Shulker Box — container tags: CustomName, lock, Items (27 slots), LootTable + LootTableSeed.
• Chiseled Bookshelf — Items (6 slots, left-to-right top-to-bottom), last_interacted_slot (−1–5).
• Command Block — auto (always active), Command, conditionMet, CustomName (default "@"), LastOutput (when TrackOutput), LastExecution (when UpdateLastExecution), powered, SuccessCount (comparator output), TrackOutput (default true), UpdateLastExecution (default true).
• Comparator — OutputSignal.
• Conduit — Target (UUID int array of current target).
• Copper Golem — no extra tags; custom name of the golem comes from the minecraft:custom_name component.
• Crafter — container tags plus crafting_ticks_remaining (6 ticks after crafting, sets crafting block property), disabled_slots (int array), triggered (1 = true, synced with triggered property).
• Creaking Heart — creaking (UUID int array of bound Creaking).
• Daylight Detector — no extra tags.
• Decorated Pot — item (held item), LootTable + LootTableSeed, sherds (4 entries back/left/right/front; minecraft:brick default; → pot_decorations).
• Dispenser / Dropper — container tags (9 slots).
• Enchanting Table — CustomName.
• End Gateway — Age (beam control: <200 ticks magenta beam; divisible by 2400 → 40-tick teleport cooldown + purple beam), ExactTeleport, exit_portal ([x,y,z]).
• End Portal — no extra tags.
• Hanging Sign / Sign — front_text / back_text each with messages (4 text component lines), color (default black), has_glowing_text, filtered_messages (chat-filtered variants); is_waxed (text locked, commands still run).
• Hopper — container tags (5 slots) plus TransferCooldown (default −1; at 0 transfers and resets to 8 ticks).
• Jigsaw Block — name (default minecraft:empty), final_state (default minecraft:air), joint (rollable/aligned), placement_priority, pool, target (defaults minecraft:empty), selection_priority.
• Jukebox — RecordItem (music disc item), ticks_since_song_started.
• Lectern — Book (written book item), Page (0-based; out of range clamps).
• Monster Spawner — spawner common tags (spawn data, spawn range, delay, potentials...).
• Moving Piston — blockState, extending, facing (0–5 = down/up/north/south/west/east), progress (0–1), source.
• Sculk Catalyst — cursors (list of spread signals: charge 0–1000, decay_delay 0/1, pos, update_delay, facings).
• Sculk Shrieker — listener (vibration listener), warning_level (default 0; sets to the activating player's warning level).
• Shelf — Items (3 slots), align_items_to_bottom (default false; uses on_shelf display transform when true).
• Skull — custom_name (→ custom_name component), note_block_sound (→ note_block_sound component), profile (game profile; string form loads then converts; → profile component). Profile textures data is Base64-decoded JSON: profileId, profileName, signatureRequired, textures with CAPE/SKIN (url, optional metadata.model = slim), timestamp.
• Structure Block — author, ignoreEntities (default true), integrity, metadata, mirror (NONE/LEFT_RIGHT/FRONT_BACK), mode (SAVE/LOAD/CORNER/DATA), name, posX/Y/Z (−48–48, Y default 1), powered, rotation (NONE/CLOCKWISE_90/CLOCKWISE_180/COUNTERCLOCKWISE_90), seed, sizeX/Y/Z (0–48), showair, showboundingbox (default true), strict.
• Test Block — message, mode (invalid → fail), powered.
• Test Instance Block — data (instance data), error_message (only when status is finished), ignore_entities, rotation, size (int array), status (cleared/running/finished), test (test instance ID), errors (list of {pos, text} markers).
• Trial Spawner — normal_config / ominous_config (trial spawner config by ID or inline: items_to_drop_when_ominous (default spawners/trial_chamber/items_to_drop_when_ominous), loot_tables_to_eject (weighted list; defaults spawners/trial_chamber/consumables and spawners/trial_chamber/key at weight 1), simultaneous_mobs (default 2), simultaneous_mobs_added_per_player (default 1), spawn_potentials (weighted spawn data), spawn_range (Chebyshev, default 4), total_mobs (default 6), total_mobs_added_per_player (default 2), ticks_between_spawn (default 40)); plus cooldown_ends_at, current_mobs (UUIDs), ejecting_loot_table, next_mob_spawns_at, registered_players (UUIDs), required_player_range (Euclidean, default 14), spawn_data, target_cooldown_length (default 36000 ticks), total_mobs_spawned.
• Vault — config: activation_range (default 4), deactivation_range (default 4.5), key_item (default trial key; absent = unlockable), loot_table (default chests/trial_chambers/reward), override_loot_table_to_display; server_data: items_to_eject, rewarded_players (max 128), state_updating_resumes_at, total_ejections_needed; shared_data (client render): connected_particles_range (default 4.5), connected_players (UUIDs), display_item.

Storage Format

All block entities are stored in the chunk's block_entities list. Storage format equals the data format plus:

• keepPacked (required) — true while the block entity is data-only and not yet added to the world (false for world-accessible ones).

During world generation, blocks with block entity data are written with keepPacked: 1 and id: "DUMMY"; they are deserialized and added to the world when the prototype chunk converts to a world chunk (or when the position is accessed), after which keepPacked becomes false.