Where IO Games Are Heading and What That Means for Players
After a decade of evolution since Agar.io, the io format is settling into recognisable subgenres with different player audiences. Here is the landscape.
Agar.io launched in 2015. In the decade since, the io-game format has evolved from a single experimental game into a thriving multiplayer subgenre with dozens of subformats and hundreds of titles. As someone who covers io games for AJ Arcade, I see the landscape settling into recognisable patterns that have implications for where the format goes next.
This article maps the current state and projects where the format is heading.
The original .io formula
Agar.io established the original .io formula. Shared map. Many players in a single match. Eat-and-grow loop. Free-for-all combat. Browser-based with no client install. The format went viral because it combined social multiplayer with the immediate accessibility that browser games offer.
The original formula has not gone away. Snake Arena X on this catalogue carries it forward. Cell Grow maintains the agar-style growth loop. The simple-format io games still attract significant audiences.
The first wave of subgenre expansion
The format expanded quickly in the late 2010s. Combat-focused io games (Diep.io, 2016). Team-based io games (Krunker.io, 2018). Battle-royale io games (Surviv.io, 2018). Each subgenre adapted the io formula to a different gameplay tradition.
The catalogue has examples of each. Tank Skirmish is combat-focused; Flag Capture IO is team-based; Arrow Hunters is battle-royale. The diversity within the io umbrella now is remarkable.
The current state
Four subgenres dominate io play in 2026.
Survival-growth io like the agar.io descendants. Browser distribution, eat-and-grow loop, broad casual appeal. Growth has stabilised; new entries face an uphill battle against established titles.
Combat-focused io like the diep.io descendants. Customisable loadouts, twin-stick combat, hardcore audience. Growth is steady; the format has room for new entries that bring real innovations.
Battle-royale io in the surviv.io tradition. Shrinking zones, limited inventory, last-player-standing wins. Growth has peaked; the format is mature.
Coordinated-team io like flag-capture or tower-rush variants. Smaller player counts per match, role-based composition, organised play. Growth is the strongest of the four subgenres because the team-based format has not been saturated yet.
What the next decade looks like
My forecast (as a player and reviewer, not as an industry analyst) is that team-based io games will dominate the next phase of the format's growth. The reasons are practical.
Survival-growth io is saturated. Combat-focused io has matured. Battle-royale io has matured. Team-based io has lots of design space left to explore. New entries that combine coordination requirements with browser distribution will find audiences ready for them.
Server Strike on this catalogue is the kind of game I expect to see more of. Ten-versus-ten tactical combat. Skill-based matchmaking. Real anti-cheat. Browser-distributed but with the quality of a small native game. This is where the format is heading.
What this means for players
If you enjoy io games, the next decade is going to be good for you. The format is going to keep producing variety. The technical infrastructure (HTML5 multiplayer, WebRTC peer-to-peer, browser-side anti-cheat) keeps improving. The economic model (ad-supported plus optional cosmetic) is sustainable enough that developers can keep producing new titles.
The games on this catalogue represent what I think the format looks like at its current best. Most are good. A few are excellent. A few are bad and get rated accordingly. Use the catalogue to find the io games that match your preferences.
The friction points
The io format has structural friction points that are worth knowing about.
Matchmaking quality varies wildly. Some games (Server Strike) have proper skill-bracket matchmaking. Most games do not. New players in matchmaking-less games get stomped by veterans.
Anti-cheat quality also varies. Browser games are inherently more vulnerable to client-side cheats than native games. Games that take anti-cheat seriously (again, Server Strike is the model) are notable for it.
Monetisation balance is the third friction point. Ad-supported io games can be fair; some are. Others use ad-walls between matches that drive players to back buttons.
What developers should learn
Developers reading this: the io format is not done growing. New entries can still succeed. The structural requirements are getting higher (matchmaking, anti-cheat, balance) but the audience is also more sophisticated and willing to support games that meet those requirements.
The winners of the next decade will be the developers who treat io games as serious multiplayer products rather than as quick browser titles. The 200-game catalogue on this site is full of examples of both kinds.
Frequently asked questions
What is an io game?
Multiplayer browser games descended from Agar.io (2015). Shared maps, many players per match, no client install required. The .io suffix became shorthand for the format.
Are io games still popular in 2026?
Yes, more than ever. The format has expanded into many subgenres and continues to attract significant player audiences across all of them.
Why are some io games so unbalanced for new players?
Most io games do not implement skill-based matchmaking. New players face veterans on shared servers. Games with proper matchmaking (Server Strike on this catalogue) are exceptions.
Are io games cheaper to develop than native multiplayer games?
Yes. Browser distribution eliminates platform fees; HTML5 lets one codebase run everywhere; ad monetisation requires no payment infrastructure. The lower costs let smaller teams ship competitive products.
What is the future of io games?
Team-based coordinated io will dominate the next decade. The other subgenres are maturing; coordinated-team formats have lots of design space left to explore.
Physics graduate who works in cybersecurity by day and reviews browser puzzles by night. The kid who solved Rubiks Cubes at lunch in school. Has opinions about constraint-satisfaction algorithms.
More from Asha →