- For stat upgrades such as Bullet Speed or Max Health, see Stats.
This page delves mostly into the base upgrades and what they branch off into. For more details on every upgrade, visit their pages, or for a briefer description, visit Tiers.
The basic Tank starts as a circle with just one Cannon. When you reach level 15, you can upgrade your tank to become a Twin, Sniper, Machine Gun or Flank Guard. The Twin upgrade adds a second cannon right next to the first, but decreases Bullet Penetration and reduces damage. The Sniper upgrade increases Bullet Damage and Bullet Speed, as well as increases the FoV (Field of View) slightly, but greatly reduces your Reload Speed. The Machine Gun upgrade increases Reload Speed and Bullet Spread, but slightly decreases your Bullet Damage. The Flank Guard upgrade adds a smaller cannon to your back, which allows you to shoot in two directions. Only selectable at Level 30, the Smasher upgrade removes all cannons and instead adds a hexagon base of the tank. This will remove all Bullet stats, but each other stat will cap at 10 Skill Points instead of 7.
When you reach Level 30, you can choose a second upgrade depending on the basic upgrade that you chose. You can upgrade again at Level 45.
- Main article: Twin
The Twin can upgrade into Triple Shot, Quad Tank, or the Twin Flank. If you choose Triple Shot, your tank’s dual cannons will move out onto the side pointing diagonally, making room for a third cannon in the middle. Triple Shot can then upgrade into Penta Shot, which adds an additional two not so spread cannons between the sides and the middle of your tank; Spread Shot, which adds an additional eight extremely spread cannons to the tank; or Triplet, which is basically a Twin with a third cannon in the middle. It shoots much faster than the Twin but has less Bullet Damage and Penetration. If you choose Quad Tank, the two cannons move to the top and bottom and add another 2 cannons to the side spread out evenly. This will increase Reload and Bullet Speed. Quad Tank can then upgrade into Octo Tank, which has eight cannons (one facing in each normally used direction), or into Auto 5, which has 5 Auto Turrets instead of regular cannons. If you choose Twin Flank, your tank will receive an additional two cannons on the back. Twin Flank can then upgrade into Triple Twin. Triple Twin will make your tank have three pairs of cannons with equal distance from one pair to the other. You can also upgrade to Battleship, which switches all your cannons for drone launchers. These launchers fire drones that attack for you, all drones die after a certain amount of time and half of the drones can be controlled.
- Main article: Sniper
The Sniper increases your range, the field of vision and bullet damage, but decreases your rate of fire. The Sniper can be upgraded into Overseer, Assassin, Hunter or Trapper. If you choose Assassin, your tank’s cannon will get longer, increase your FoV even more and decrease your Reload even more. The Assassin can then upgrade to Ranger, which increases your tank’s FoV and bullet penetration even more and decreases Reload even more; or Stalker, an Assassin which can go invisible. If you choose Overseer, you will have two Spawners on the side of your tank and controllable Drones instead of bullets. Overseer can then upgrade to Overlord, which has two more Spawners and adds controllable Drones; Manager, an invisible Overseer with one Spawner; Necromancer, a square-body Overseer which controls a huge army of Square Drones instead of a small troop of Triangle Drones; Overtrapper, which shifts the two Spawners to the back and adds a Launcher to the front; or Factory, which has 1 minion launcher and shoots small minions that attack the nearest thing that provides XP and can also be controlled. Overseer can also upgrade to Battleship which has 4 drone launchers that fire small and weak drones. The Battleship can have an infinite amount of these drones. The drones only last a certain time and will die. If you choose Hunter, a second cannon will overlap the first one and shoot an extra bullet every shot. Hunter can then upgrade to Predator, which adds one more cannon (and thus one more extra bullet) and an ability to concentrate your FoV in a certain direction, or Streamliner, which has a cannon in 5 segments and shoots lots of bullets at an incredible rate. It formerly could upgrade to X Hunter or the old Predator. If you choose Trapper, the cannon will be replaced by a Launcher which launches Traps instead of bullets. Trapper can then upgrade to Mega Trapper, which has less reload but biggest traps; Tri-Trapper, which has three Launchers instead of one, yet short lifespan; Gunner Trapper, which shifts the Launcher to the back and adds two Gunner cannons to the front; or Auto Trapper, which adds an Auto Turret on top.
- Main article: Machine Gun
The Machine Gun increases your Reload speed and decreases Bullet Damage, plus it covers a wider area. It can be upgraded into the Destroyer, Gunner or Sprayer (formerly Destroyer and Machine Gun II). If you choose Destroyer, your cannon is replaced to shoot huge strong bullets but has drastically decreased Reload and Bullet Speed. A popular way of using this type of tank is to use the recoil to launch yourself into other tanks when you have fully upgraded your Body Damage and health (Rammer Build). Destroyer can then upgrade to the Hybrid, which adds a Spawner to the back; Annihilator, which makes the cannon wider and increase its recoil; or Skimmer which shortens the Destroyer cannon and adds a trapezoid cannon behind it, shoots Missiles which themselves have 2 small cannons on either side (similarly to a Flank Guard), which also spins around clockwise. Destroyer can also upgrade to Rocketeer, which replaces the Destroyer cannon with a shorter, trapezoidal cannon and also adds another trapezoidal cannon behind it, and shoots Missiles which has a trapezoidal cannon on the back (similar to a backwards-facing Machine Gun), which fires Bullets towards the Rocketeer and propels itself with Recoil. If you choose Gunner, your cannon is replaced by four tiny cannons that shoot small, weak bullets but has drastically increased Reload. Gunner can further upgrade to Auto Gunner, which adds an Auto Turret on top; Gunner Trapper, which removes two of the Gunner cannons and adds a Launcher to the back; or Streamliner, which has a cannon in 5 segments and shoots lots of bullets at an incredible rate. Only possible at Level 45, you can choose the Sprayer. If you choose Sprayer, you get an extra tiny cannon inside your cannon which ejects bullets and mini bullets at the same time but decreases Bullet Damage even more.
- Main article: Flank Guard
The Flank Guard adds a half cannon on the back of the tank which shoots at the same time as the other one. It can be upgraded to the Twin Flank, Quad Tank, Tri-Angle or Auto 3. If you choose the Tri-Angle (the second-fastest tank in the game), the half-cannon on the back becomes two half-cannons, forming a triangle. The Tri-Angle can further upgrade into the Booster, which adds two more guns behind the tank, doubling its acceleration; or the Fighter, which adds two additional guns to the side, increases Bullet Damage. If you choose Quad Tank, another 2 cannons are added to the side of the tank. This will increase Reload and Bullet Speed. Quad Tank can then upgrade into Octo Tank, which has eight cannons (one for each normally used direction); or into Auto 5, which has 5 Auto Turrets instead of regular cannons. If you choose Twin Flank, your tank will receive an additional two cannons, one on each side. Twin Flank can then upgrade into Triple Twin. Triple Twin will make your tank have three pairs of cannons with equal distance from one pair to the other. Twin Flank can also upgrade to Battleship, which replaces the cannons with drone launchers that fire small drones that attack for you. Only half of these drones are controllable. If you choose Auto 3, your cannons will be replaced by 3 Auto Turrets. Auto 3 can then upgrade into Auto 5, which has 5 Auto Turrets instead of 3, or Auto Gunner, a Gunner with an Auto Turret on top.
- Main article: Smasher
If the player chooses to stay as a basic Tank until level 30, you can upgrade to Smasher. If you choose it, the cannon and all Bullet stats are removed, and a hexagon base is added to the tank. All other stats cap at 10 Skill Points instead of 7 with this tank. This tank can upgrade to the Landmine (formerly Mega Smasher and Landmine) at Level 45. The Landmine is a Smasher with another hexagon that spins twice as slow but it can turn invisible for 10 seconds. You can also upgrade to Auto Smasher, which adds an Auto Turret on top of the Smasher’s body and all Bullet stats are back a cap at 10; or to Spike, which has twelve black spikes which spin very quickly and increases base Body Damage.
- Main article: Machine Gun II
The Machine Gun II (in-game Machine Gun) used to upgrade from the Machine Gun. It looked the same, had faster, more damaging bullets and less spread (sort of like the Sprayer). It was removed in the update that added the Gunner.
- Main article: Mega Destroyer
The Mega Destroyer (in-game Destroyer) was the fan name given to the Destroyer when it upgraded from the Machine Gun II. Apart from that, it was no different from a regular Destroyer.
- Main article: Mega Smasher
The Mega Smasher used to upgrade from the Smasher. It had a thicker hexagon around it. It further increased knockback resistance. The knockback resistance on the regular Smasher, the Landmine and the Mega Smasher was removed later. It was thus removed for being useless.
- Main article: Predator
The Predator used to be quite different when the X Hunter was still around. It looked like the X Hunter but with the largest cannon instead being a trapezium, like on a Ranger’s cannon or a Dominator’s Cannon. It shot only two bullets like the Hunter currently does but had the zooming ability that it still has now.
- Main article: X Hunter
The X Hunter used to upgrade from the Hunter. It looked like the Predator does nowadays. It shot three bullets just like the Predator does but lacked a zooming ability. It was merged with the Predator and then was removed.
- Main article: Mothership (Tank)
The Mothership tank was exclusive to the defunct Mothership game mode and impossible to upgrade to. In this mode, random players would become their team’s Mothership; the same goes for the enemy team. The Mothership was level 140 and had all upgrades maxed out except Health Regen (Health Regeneration is only upgraded once). It spawned 16 controllable Drones and 16 uncontrollable ones to survive. These Drones could be destroyed albeit having high health. The two players to join a server first would control the Motherships for the Red and Blue team. They had 5 minutes in control of the Mothership before 2 new players took control of their team’s Mothership.
The Mothership was kept around in Sandbox. However, it behaved like a regular tank and could only be accessed by pressing \. The Mothership has since been fully removed from Diep.io.
- Main article: Arena Closer
When the arena is being closed, the server will spawn many Arena Closers to remove all the players from the server and start a new game. The Arena Closers seem to be fully upgraded, without any reduction in speed, strength, or other upgrade side effects. There is no possible way to receive this upgrade in-game. It is possible to destroy an Arena Closer, however, it has such a large amount of health, that attempting to destroy it is not worth it. Its damage stats are so high that they will kill you extremely fast. Also, the quicker you are killed, the quicker you get to play again, so it is recommended to let them kill you. Arena Closers were playable only in the Sandbox mode. Thay have since become nonplayable.
- Main article: Dominator
This tank, like the Arena Closer, is impossible to upgrade to. It shoots large Destroyer bullets that can instantly kill most enemies. However, its reload is rather slow and can only hit one enemy at a time, leaving it vulnerable for attack. It has an immense amount of health; more than 2 times an Alpha Pentagons. The Dominator is initially controlled by an AI but can be player controlled through pressing H when a Dominator is captured. There is also a Gunner Dominator, with 3 powerful Gunner cannons or Trapper Dominator with 8 Trap Launchers. The Dominator is playable by pressing H in the Domination game mode when your team captures it. Press the button quickly, as many people will want to become a Dominator. It was playable in Sandbox but has been removed from that mode.
The lower the ID the tank is, the earlier the tank was added. In Sandbox mode, pressing the \ key will cycle through these in ID order (highest to lowest) with minor changes. Special tanks can only be obtainable in Sandbox and tanks with italic, darkened names are removed.
- Triple Shot
- Quad Tank
- Octo Tank
- Machine Gun
- Machine Gun II
- Flank Guard
- Mega Destroyer
- Twin Flank
- Penta Shot
- Arena Closer (Special)
- Triple Twin
- Destroyer Dominator (Special)
- X Hunter
- Gunner Trapper
- Mega Trapper
- Mega Smasher
- Auto Gunner
- Auto 4
- Auto 5
- Auto 3
- Spread Shot
- Auto Trapper
- Gunner Dominator (Special)
- Trapper Dominator (Special)
- Auto Smasher
- Mounted Turret