Debug mode

Debug mode is a world type used to test block states, block models, and textures.

Accessing


To select the debug mode, hold the key while clicking the "World Type" button in the world creation menu. Debug mode is the world type directly after Floating Islands, and just before Default.

Upon selecting debug mode, the "Bonus Chest", "Generate Structures", and "Allow Cheats" options are removed from the menu. The game mode is set to Spectator, and the difficulty is locked on peaceful; however, and  work as usual within the world.

Properties
Debug mode contains all blocks, in all of their existing block states, organized in a single world. The world updates automatically to include any new registered block IDs that are added. Therefore, this mode is useful not only to Mojang developers, but also to creators of resource packs and mods.

Block grid
Every block state generates only once. They are sorted in a grid spread across an altitude of y=70. The block grid changes its size according to the number of blocks and block states available, roughly resembling a square (as of 1.14.2, 213 in width and 211 eastward), occupying the +X,+Z (southeast) quadrant.

A barrier floor at y=60 also spawns, extending past the grid in all directions to the world border. Other than the barrier floor, the remainder of the map is empty.

Other dimensions


If a Nether or End portal is used, or teleported using, the player spawns in a Nether version or an End version of the debug world, respectively. The sky, light level and other properties remain appropriate to the dimension.

In the End, the ender dragon and its end crystals still spawn, although the dragon cannot break or interact with blocks. If the end portal is used in the End, the end poem and credits appear as normal. If using an ender pearl to utilize the end gateway portal, the gateway teleports the player, but in keeping with debug mode world generation, neither outer islands nor a returning gateway portal generate.

Block behavior
It is impossible for the player to place any block, even in game modes in which they otherwise could. Also, the, and  commands cannot be executed.

Any block whose interactions do not change its block state can still be (including chests, beds, cake, etc.). Although a block's state cannot change, its block entity data can change, either through normal player interaction or with the use of the command.

These unique properties of debug mode can cause certain blocks to behave in unexpected ways, though due to the arrangement of blocks next to one another, not all may be seen in every version:


 * Water and lava cannot be removed by buckets, but still fills an empty bucket in Survival mode. If the player empties the bucket, the lava or water blocks turn invisible.
 * Bells can still be rung.
 * Cauldrons clean leather armor and banners, but cannot be filled by buckets.
 * a button or lever drops one of itself as an item.
 * Activating those blocks schedules a block tick for its own block, which drops one of itself because those blocks cannot be suspended in mid-air.
 *  Warning:  a pressure plate with powered stated false, or a weighted pressure plate with power state 0, causes it to generate enormous quantities of dropped plates, likely crashing the game. It also produces an extremely loud sound from so many pressure plate sounds being played at once.
 * The pressure plate schedules a block tick for itself, and drops an item because it cannot be suspended in mid-air.
 * Since it never changes to an activated pressure plate, it never stops receiving activation from the entities and/or items on it, and never stops scheduling block ticks.
 * Certain pressure plates, when activated, cause an error in the game output, stating that the dropped item entity has no entity.
 * a comparator in subtract mode, a lever or an unpowered button causes the block in the direction opposite its  property to drop as an item.
 * If that block is a repeater or a comparator, it drops of itself.
 * It starts to repeatedly schedule its own block-state-changing tick, which fails continually a large number of times.
 * These types of blocks schedule a block tick in the adjacent block.
 * If that block could not normally remain suspended in the air, it drops one of itself as an item.
 *  Warning:  placing a minecart on an unpowered detector rail drops an infinite number of detector rails, crashing the game.
 * Certain glass panes, iron bars and fences have incorrect hitboxes.
 * Any summoned falling_block entities drops as an item when it hits another block, rather than converting itself to a block. Such a summoned falling block immediately drops as an item, rather than fall any distance.
 * fence gates, comparators, deactivated buttons, levers, deactivated pressure plates, doors, or trapdoors does not move or change the block, but the sound still plays.
 * Nether portals are visible, but the End portal is not.
 * Shulker boxes are invisible until looked at.
 * Using a music disc on an empty jukebox does not change its block state but still plays the music normally.
 * Firework rockets do not boost the player while flying with elytra. Instead, the rocket flies upward as if it was used while looking at a solid block.

Trivia

 * The set biome for this mode is plains by default in the Overworld.
 * The sun is displayed as if it were the beginning of the day (time 1000), but the daylight cycle is disabled.
 * Regardless, the time can still be adjusted with the use of the command, and the daylight cycle can be toggled with the use of the  command. The time can be also advanced from nighttime to sunrise with the use of a bed.
 * Using a map does not create an accurate map of the blocks in the world.
 * This type of world is the only type where barriers spawn naturally.
 * After setting the world type to Debug Mode, the Game Mode button is locked in Spectator, and a line of text appears beneath: "You can look but don't touch".
 * There is, however, nothing preventing you from changing the game mode using commands, as long as you have cheats enabled.

Gallery
Debug-Modus Mode de débogage デバッグモード 디버그 모드 Tryb debugowania Режим отладки 调试模式