Hellooooo, ladies and gentlemen. As you understand from the title of this topic, today we will talk about hitboxes of the tank and the possibility of a headshot. This oooold as hell and booring as ......I dont know what. So why is this a well-known and boring topic? Because until now some players believe in the existence of this headshots. The answer "the increased damage at a head shot to the tank does not exist" does not convince those people at all and they stand one's ground, asserting the opposite.
So, let's start from the beginning. Cant say that the tank does not have a hitbox of the head. Because of the small anatomical features of the tank, there are 2 hitboxes in his head: a head (a large box) and a neck (a small box). None of these hitboxes is special and has no increased damage.


Knowing that the answer is "no" is not convincing, let me introduce to you 2 experiments.
1) Headshot
The meaning is simple. With the help of weapons to shoot at all hitboxes of the tank. Having information about the damage of a particular weapon (in this case - a sniper rifle), you can determine whether there is an increase in damage when firing at any hitbox.
2) Neckshot
A more serious thing than just firing in the tank's noggin. Using a sniper rifle you need to hit the hitbox of his neck. And if suddenly the damage is increased - you can say that headshots are possible. The problem is that this hitbox is rather small, and well hidden in the body of the tank. In the pictures you can see that this hitbox is almost always inside. (Even if tank is running that creepy way. It's good that animation is not used in the game. If something were run to me like this, I would not go out from the saferoom without the RPG)

Running Tank

Creepy Tank
To shoot through this little hitbox, you need to make tank open his throat, which he does during "taunt." At this point, the tank raises its head, the hitbox of the chest is bent down, and from the neck to the hitbox there appears the minimum distance that a sniper rifle is the easiest task to pierce. Accordingly, to get into the hitbox you need to: tank’s “taunt” and shoot exactly into the area of the tongue and throat.


As expected - experiments completely disprove the increased damage when firing at the head area. Each shot was counted as a normal hit without any increase in damage. So it does not matter whether you are shooting in the heel, or in the head.
As for Left 4 Dead 2, there are absolutely similar results. Tank have no increased damage in head-area, so as his L4D1 brothers.