IO games are usually free to play, simple, browser-based games that have some sort of multiplayer element to them. They don’t necessarily need to have .io as their domain name, but their simplicity is what sets them apart from other games out there.
It is also this simplicity and easy accessibility that contributes to their immense popularity. These games are simple, easy to play and of course don’t need any installation.
Interestingly, the .io extension has nothing to do with games. It is just the country code top-level domain for the British Indian Ocean. The biggest and the first two IO games, Slither.IO and Agar.IO, used .io as the domain of choice and from there on it became the default choice for io game developers.
In this article, we take a look at the top seven IO games you can spend hours on
Also read: Top 15 browser games for PC
Agar.io
Agar.IO, the first of IO games is a massively multiplayer browser-based game made by a Brazilian developer Matheus Valadares. It was released for web-based play on 28 April 2015.
Each player is given one cell in a map representing a petri dish. The goal here is to be the ultimate cell on the map. Players can grow their cells by eating agar(a substance used to culture bacteria) or consuming other smaller players’ cells.
Once a cell reaches enough mass, they can even split in two giving the player the ability to control more than one area on the map. There are also four different game modes that you can choose.
Slither.io
Another hugely popular io game, Slither.io is Snake on steroids.
The game acts, plays and feels precisely like Snake. You need to consume food to increase in size and keep going on. However, here’ the multiplayer element — there are other snakes on the map too, controlled by other people. The objective is to be the last snake standing.
You can consume other people’s snakes by making their heads collide in your snake. When a snake dies, it leaves behind food orbs of growth points equivalent of its size, so be sure to grab them before anyone else does.
Vanar.io
This game easily makes for some of the most chaotic online combat you’ll ever see in a browser game.
Vanar.io puts you in control of a space ship. As you fly along, you’ll continuously be pelted with asteroids which you’ll have to avoid. Sounds easy enough?
Well, did I forget to mention there will be other players as well, in bigger spacecraft, shooting lasers at you? Yeah, you need to avoid asteroids and incoming fire from other spacecraft to survive, grow in size and be the last shuttle standing.
The controls are straightforward, and you get a combination of a shield and lasers to defend/attack. Vanar is also one of the most stylish and best-looking io games that you’ll come across.
Also read: How I got my Steam account hacked and what I learnt from it?
Tankwars.io
Another hugely popular io game, tankwars.io puts you in control of a tank, in the middle of the desert, surrounded by other tanks which are trying to blow you up. The goal? Survive.
The game provides immediate action from the second you spawn till you die. There are a host of weapons to choose from, and you can even call in air support.
Tankwars.io is yet another example of a simple, browser-based game that manages to blend in attacking gameplay with strategic defence quite naturally. It also looks great.
Vertix.io
If you’re more into top-down shooters, you’ll definitely like this one.
While the perspective is a bit skewed here, Vertix.io makes for a very simple and a very fast-paced arcade-style shooting game. You hop on a concrete map and run around trying to kill the other team. That’s it.
There are different classes available, with each one having its unique perks. You can even customise your character nad guns with different skins. The game also allows you to make custom servers and play with your friends only if you want.
Also read: Top 11 RPG games for Android
Diep.io
Similar to Agar.io in many ways, Diep.io puts the player in charge of a blue dot that has to shoot its way to victory.
As the player eliminates more coloured objects around them, their dot can be upgraded to be faster, larger, shoot further or branch out into further divisions/classes.
The action progressively increases as the player spends more and more time, eventually becoming the most dominant player in the game.
Zombs.io
If you’re into zombie games, this one is a must-try. Zombs.io follows a very similar gameplay style to most zombie games. 
You build your settlement and gather resources during the day and defend them from zombies during the night. The appeal here is that being an io game, it makes the barrier of entry to the action disappear.
The game has numerous type of buildings and perks you can create to push back wave after wave of zombie hordes. As you progress in the game, you get access to better buildings/weapons, and the zombies become stronger as well.
Also read: Top 10 FPS games for browsers
