How to despawn mobs automatically?

Hi! I am new here and you may probably say use /killall but still not helping. My friend made a spawn, its in the sky lol. anyway, mobs keep spawning and i keep doing /killall but its useless so anyway to kill or despawn mobs automatically? :S

Please help asap!

 

/butcher is the command you are looking for. You can also disable mobs in the server properties if you want

 

iZat234 with worldguard you can stop mob spawn in the area.

 

Its not helping me still! /butcher fails, they keep freaking spawning back.
SuperOmegaCow Does it stop it from spawning, like when they spawn they automatically despawn, i hate doing killall all the time :I

 

iZat234 worldguard stops all mob spawn in the area that you select.

 

Alrighty! Thanks for helping, will be sure to visit again for more requests and stuff like that