Why are my creepers not spawning?

I built a creeper farm recently (illmango's design). On his video, the creepers were spawning pretty frequently, but I don't get as many spawns. (I get some spawns, just not the ratio I was hoping for.) Is this because I'm on an online server? (5-20 players online most of the time) or is there any other problem?

Solution 1:

Spawn rates are dispersed among all players that are currently logged in to the server. If you keep an eye on your farm, you will notice a vast difference between when there is 5 players online, and 20.

For each player that is currently online, there is a valid spawning area around each player.

As an example, let's say the mob cap is 100. If there is 5 players online, then that means ~20 mobs will be spawning near each player, including you at each interval. If there are 20 players online, that will drop to ~5.

Depending on where each player is can affect whether or not mobs can spawn, for example if a player is in the nether, or in a well lit area, this reduces the amount of mobs that can spawn near that player, which can increase your farm's spawn rates. If a player is in a cave, or out in the wilderness during nighttime, mobs will be able to spawn around them, reducing your farm's spawn rates.