Best IO Games by Genre in 2026, With Live Status Checks

Checked: October 28, 2026, between 17:02 and 17:08 UTC (Play links: November 3). Server counts from the games' own public endpoints; update dates from official changelogs, the App Store and Google Play.

The status board

A note on the dates: an App Store update is proof that a studio still ships builds, not that the browser version changed the same day. Where a game publishes its own changelog (Mope.io, Krunker, TETR.IO), we used that instead.

Cell eaters and their descendants

The App Store release dates give a rough family tree. Agar.io arrived on iOS on July 8, 2015, Slither.io on March 25, 2016, Diep.io on July 20, 2016 and Mope.io on November 3, 2016. Diep.io's own store page even opens with "From the creator of Agar.io". Each one reworks the same loop: grow by eating or shooting, and avoid anything bigger than you.

Image: Mope.io App Store screenshot (VexxusArts Ltd)

Agar.io is the oldest game here and the busiest one we could count. Miniclip's public server feed listed 2,401 players across 61 servers at 17:08 UTC on October 28. London had 775 of them, Brazil 640 and Atlanta 466; the China and Russia regions showed zero. If you play from Southeast Asia, expect thin lobbies: Singapore had 35 players at 1 a.m. local time, and only 57 when we checked again at 2 p.m. Singapore time on October 29.

Mope.io is the one we would pick today. The store page sums it up as "climb the food chain", one animal at a time, and the developers are clearly still at it: the in-game changelog lists patch 2.017.1 on October 2, 2026, with a fix for the Kraken's whirlpool and a tweak so rare pumpkins keep their bonus while carried. That is the freshest dated patch note among the classics.

Slither.io still loads and still works, but it publishes no player count, and its iOS app was last updated November 10, 2025. It is fine for ten minutes of snake. We would not call it maintained in the way Mope.io is.

Tank shooters: Diep.io

Diep.io turns the cell formula into a tank shooter: destroy blocks and other players for XP, choose which stats to boost, and upgrade into new tank classes. When we loaded it on October 29, the mode picker offered FFA, 2 Teams, 4 Teams, Maze, Domination and Sandbox, plus Custom Games and a Halloween skin shop (Ghoul, Mummy, Vampire). The iOS app, published by VexxusArts Ltd (the same seller as the Mope.io app), has not been updated since November 4, 2024. The public leaderboard endpoint we queried returned no regions, but the front-page region picker shows a live count per server: Frankfurt had 102 players at 06:01 UTC on October 29. Our read: the web game is alive and decorated for the season, the app is not the version to judge it by.

Shooters and battle royale

Krunker is the busiest shooter we could measure. FRVR's matchmaker listed 426 lobbies holding 725 players at 17:08 UTC on October 28. Update 10.0.4 runs a Candy Heist Halloween event until November 7 and added an Interact button on mobile. It is fast, and new players will die a lot. If your friends already play shooters, our guide to browser games to play with friends covers its private lobbies; if they do not, start elsewhere.

ZombsRoyale.io brands itself "100 Player 2D Real-Time Battle Royale", and the developer's own App Store art advertises Solo, Duo, Squad and 50v50 modes. The iOS app was updated on October 27, 2026, the day before our check, which is about as alive as a 2018 game gets.

Image: ZombsRoyale.io App Store screenshot (developer: Yangcheng Liu)

For something slower and cooperative on Steam instead, Risk of Rain 2 multiplayer is the four-player answer, and our Paperhead preview covers a fast boomer shooter from February's Next Fest.

GODEEPER: Halloween is everywhere this week, from Krunker's Candy Heist to Diep.io's skin shop. The Far Far West Halloween event is the Steam co-op version, with its own dates and rewards.

Kart combat: Smash Karts

Smash Karts is a kart deathmatch with no finish line. Tall Team's store listings describe rounds of up to 8 players, power-ups such as machine guns, mines and rockets, and a three-minute timer where the most kills wins, plus private games for you and your friends on any level. The iOS app updated on October 2, 2026, and the Android one on September 30. It needs WebGL: in our headless test browser it never got past the loading bar, so check that your laptop has hardware acceleration on.

Image: Tall Team, Smash Karts App Store screenshot

Sandbox and puzzle

Bloxd.io is a block-building sandbox that has turned into a hub of player-made modes, from Bedwars and Skyblock to OneBlock. Its front page sorts custom games into Minigames, PvP, Modded Survival, Parkour Obby, PvE, Horror, Roleplay and Simulator, with a shelf for recently updated ones. The iOS app, renamed "bloxd.io: Bedwars & OneBlock", was updated on August 11, 2026.

TETR.IO is the pick for two people who take block puzzles seriously. Its patch notes are dated, which we wish every .io game did: BETA 1.7.8 on April 1, 2026, a Fool's Day mod called Mutation that swaps out the usual four-square pieces, and BETA 1.7.7 on February 13 for the Lover's Day Duo event. No newer patch was listed when we checked on October 28, so treat it as stable rather than busy.

skribbl.io is the outlier: its last front-page news post is from November 9, 2022, yet private rooms with up to 20 players worked when we opened one on October 28. It is a drawing game rather than an arena game, and it sits better in a party night than a solo session. For more like it, see our browser party games list, which compares it with Gartic Phone, or the indie social deduction picks if your group prefers lying to drawing.

Evolution brawlers and the app-first crowd

EvoWars.io starts you as a caveman; you collect orbs and beat other players to evolve, and the App Store page counts 39 evolutions across Free For All, Team and Duels modes. The website redirects to build 2.18.14, a little ahead of the iOS app's 2.18.9 from December 9, 2025. Small, alive, unglamorous.

Paper.io 2 and Hole.io are the surprise of this list. Both still get iOS updates (Paper.io 2 on October 22, Hole.io on the day we checked, October 28), but the old web addresses now redirect to Voodoo's app pages. If you specifically want them in a browser, the developer no longer points you there. We would rather tell you that than link a copycat site. If a free game on your phone is the real goal, Pokémon Champions is free-to-play on iOS and Android with cross-play; our Pokémon 30th anniversary roundup covers it.

GODEEPER: If an io game is a way to kill time between bigger sessions, our best roguelike games list and indie games under $20 are where those sessions usually start.

What we left off, and why

Some well-known names are missing from our best io games list on purpose. Florr.io and Deeeep.io blocked our automated check with a 403 on October 28, so we could not confirm anything about them from their own sites. MooMoo.io stopped at a "Just a moment" screen in our headless browser on October 29. Starve.io loaded on our October 29 re-check, with 163 players across its servers, but that came after this list was built. Surviv.io still serves a page, but its Kongregate iOS app has not been updated since June 1, 2021, and we could not find a dated update to cite. We also skipped "unblocked" mirror sites entirely: we only link a game from its own developer's site or store page.

For co-op on Steam with the same group, the best co-op games list and the Next Fest co-op demos are the next stops.

References

1. Agar.io server info feed (queried October 28, 2026) and Agar.io on the App Store, Miniclip
2. mope.io changelog and mope.io on the App Store, VexxusArts Ltd
3. slither.io on the App Store, Lowtech Studios
4. diep.io on the App Store, VexxusArts Ltd
5. ZombsRoyale.io and ZombsRoyale.io on the App Store
6. Krunker version notes and Krunker matchmaker game list, FRVR
7. SmashKarts.io on Google Play and on the App Store, Tall Team
8. bloxd.io and bloxd.io on the App Store, BLOXD LTD
9. TETR.IO patch notes, osk
10. EvoWars.io on the App Store, plus Paper.io 2 and Hole.io from Voodoo
11. skribbl.io and surviv.io on the App Store (Kongregate)