Minecraft: Can Mobs Spawn on Glass? (& Other Transparent Surfaces)

Before you build your shelter or any kind of building in Minecraft, it’s probably a good idea to spawn-proof it against pesty mobs. In our previous guides, we’ve covered the mechanics of mobs spawning carpet and on stairs. Today, we’re going to focus on another type of block that can be used for building: transparent blocks. Before we discuss the spawning conditions in more detail, it’s time to analyze the basics first. So, can mobs spawn on glass in Minecraft and other transparent surfaces in general?

What are transparent blocks in Minecraft?

Transparent blocks in Minecraft are blocks with maximum or partial transparency. Since the game has no way of knowing whether something is a solid block or not, it uses the opacity or rather transparency of the block to decide whether it needs to draw behind the block.

Some examples of transparent and partially transparent blocks that can be used for building or decorating are glass, ice, cobwebs, leaves, sea lanterns, glowstones, vines, and many other blocks.

This is just the summary of the list, as there are many other transparent or partially transparent blocks that the game’s engine views as such.
Most transparent blocks used for building and decorating are obvious as such and easy to recognize.

Can mobs spawn on glass in Minecraft?

Mobs cannot spawn on glass, they also cannot spawn on the tinted and stained glass as well. The light will not pass through the tinted glass, but it still disables the spawning of mobs. As well as disabling spawning, glass blocks the mob’s line of sight, the mechanic that allows for a mob to focus and engage in combat with the player.

However, mobs are able to pathfind around the glass blocks; if you’ve picked up “aggro” from the mobs, for example, outside of your shelter, the mob will still be able to follow you inside your shelter. The aggro rule works only for mobs and players separated by glass blocks.

As you can see, due to their unique properties, glass blocks are an excellent choice when it comes to building and decorating your shelter. They offer double protection against mobs both in terms of spawning and aggro.

Can mobs spawn on transparent blocks in Minecraft?

Mobs usually cannot spawn on transparent and partially transparent blocks. The only exception to this rule is the scaffolding block that will not deter the mob from spawning. Mobs are able to spawn on top of scaffolding blocks only in the Java edition. In the Bedrock edition, the block acts like other transparent and partially transparent blocks in Minecraft.

Can mobs break through the glass in Minecraft?

Mobs cannot break through the glass in Minecraft, but certain effects of the mobs, such as Ghast fireballs and Creeper explosions, can break glass blocks indirectly.

We’ve learned that glass is, in theory, good protection against mobs since they cannot spawn on glass blocks. There are however a few mechanics to keep in mind.
If Zombies decide to call upon Zombie Reinforcements, zombies will appear in the areas that were previously considered “protected.” While zombies are still unable to spawn on glass blocks, they can easily appear in an area where glass blocks are placed due to somehow “sneaking in.”

The other mechanics are blast related. Glass blocks have a much lower blast resistance when compared to most other blocks. The blast resistance of a glass block is set to 0.3.

To survive Ghast’s fireball, the block needs to have at least 3.5 blast resistance to absorb all damage and survive. Glass blocks are far from that and likely won’t survive if targeted with the fireball.

The same goes for Creeper explosions as well. Creeper’s explosions are much more potent and destructive when it comes to glass blocks and are sure to annihilate them. We don’t even have to mention what Charged Creeper’s explosion can do to your shelter decorated with glass blocks. It likely won’t survive the explosion.

And that’s about it. As you can see, glass, as well as other transparent and partially transparent blocks, are a good choice for building and decoration as the majority of the time, they can stop the mobs from spawning.

Glass blocks are an excellent aesthetic choice for deterring mobs. The only thing to keep in mind is the block’s relative inability to absorb blasts. The low blast resistance of glass blocks makes them especially vulnerable to Ghasts and Creepers.

Have something to add? Let us know in the comments below!