Find your first bite
Walk over fruit, donuts and burgers to gain mass. Get comfortable in Practice before entering a public arena.
A bigger appetite. A bigger adventure.
Start small. Fill up on food. Become the biggest appetite in the arena.
Fatter.io is a 3D browser game about growing, surviving and choosing your moment to attack. Outgrow your rivals, use cover and abilities, and watch your back: there is always someone hungry.
Pick your battles
Chase smaller opponents and stay clear of bigger ones. Sprint, jump, split and use your ring to change the fight.
Grow to the top
Climb the leaderboard. The mass of your surviving split bodies counts together toward the round's winning target.
Your character. Your colours.
Same appetite.
A different look.
Explore flags, army styles and colours in the Skins menu. Search by name or browse a category, then select a skin to equip it.
Skins change your appearance. They use the same gameplay dimensions, so choosing a different look gives no size advantage.
Made by two brothers
We are building Fatter.io together and improving it as we play. The game includes public online arenas and a local Practice mode with bots. You can share feedback or report a problem through Contact Support in the game menu.
Get your bearings
Small steps.
Big appetite.
Choose a nickname, then press PLAY for an online arena or Practice to learn against bots. Public arenas can contain both players and bots.
Keyboard & mouse
- W A S D
- Move
- Mouse
- Look and aim
- Left click
- Bite
- Space
- Jump
- Shift · hold
- Sprint
- C
- Split
- E
- Release a charged ring
- X · hold
- Look around freely
- Esc
- Open the menu
- M / F11
- Sound / fullscreen
Phone & tablet
Turn your device sideways to play.
Left side: move
Touch and drag to bring up the movement joystick. The camera follows your heading.
Right side: look
Swipe to turn the camera while moving. Use the action buttons to bite, jump, split and release a ring.
Hold the sprint button for extra speed. Use look back to check behind you, or pause to open the menu.
Know your next move
Food, boosts and a few tricks. Tap a card to see how it works.
Eat & growFood & growthSmall snacks. Bigger you.Auto-pickupMore massHow it works
Walk over fruit, donuts and burgers to collect them automatically. Food adds mass and calories, helping your character grow.
Keep in mind Bigger characters move more slowly at their normal pace. Pick your next chase carefully.
Power-upEnergy drinkA little can. A quick getaway.Speed boostTemporaryHow it works
Pick up a can for a temporary speed boost. Use the extra pace to chase a target or put some distance between you and a hungry rival.
Keep it going Another can refreshes the boost. It does not keep multiplying your speed.
Ability · ERing waveCharge it. Release it. Make room.Spills enemy massBrief slowdownHow it works
Eating an enemy split body adds a quarter charge. Eliminating an opponent fills the ring completely. When it is ready, press E or the ring button to release a wave.
The wave makes opponents it hits spill mass and briefly slows them down. Bushes do not block ring waves.
Jump the wave A well-timed jump can clear it. Picking up loose mass fragments does not charge your ring.
Action · BiteBite & chaseSize helps. Timing finishes the job.Face your targetGet closeHow it works
Face a smaller opponent, close the gap and use left click or the bite button. You must be sufficiently heavier than the body you are trying to eat.
Watch the hint “Get closer” means you are out of reach. Spawn protection and cover can also prevent a bite.
Move · SprintSprintSpend a little size to gain some speed.Hold to sprintCosts massHow it works
Hold Shift on a keyboard or the sprint button on touch screens while moving. Sprinting trades mass for extra speed.
Choose your moment Release sprint when you no longer need the extra pace to stop spending mass.
Ability · CSplitOne appetite. A few more bodies.Launch forwardMerge laterHow it works
Press C or the split button to launch a smaller body forward. Your surviving bodies reunite after the merge delay.
Size matters Each smaller body is easier for an opponent to eat. Splitting can open an opportunity and leave you exposed.
CoverBushesA small hiding spot for a smaller you.Bite protectionFit fully insideHow it works
A bush protects you from bites while your whole body fits inside it. Stay within its cover to keep that protection.
Mind the edges Growing or jumping can expose you. Bushes do not block ring waves.
Hazard & coverThorn trapsA big problem. A small escape.Weight limitSlows youHow it works
Check the weight shown on a thorn trap. A body heavier than that limit spills 25% of its mass as collectible fragments when it touches the cactus. The cactus immediately disappears for everyone, and the hit body is 20% slower for 3 seconds. Each cactus can hit only once. Jump over it to avoid the hit.
Small-body shelter A body at or below the limit can shelter there without consuming the cactus, but cannot bite while sheltered. Ring waves still reach you.
PickupMass fragmentsSomeone's lost mass. Your next meal.Recover massLet it landHow it works
Cactus hits and ring waves scatter collectible mass fragments. Let them land, then move over them to collect the mass.
A short wait Your own spilled fragments have an extra collection delay. These pickups do not charge the ring.
A little help, a better game
Back to
the arena.
Quick answers for your next round.
Why can't I eat another player?
You may be too small, too far away, or facing away from them. Spawn protection and cover can also prevent a bite. Look at the targeting hint: “Get closer” means you still need to close the gap.
Does opening the menu pause an online match?
No. The online arena stays active, so other players can continue moving and attacking while your menu is open.
The camera stopped following my mouse.
Choose Resume or click inside the game to return control to the game window. On touch devices, swipe the right side of the screen to look around.
The game is slow or won't load.
Try a lower Graphics setting and close other demanding tabs. If loading fails, reload the page and check your connection. Practice is a useful way to check your controls before joining online.
If the problem continues, send your device, browser, a screenshot and the steps that led to it through Contact Support.
How do I join my friend's game?
Use a fresh invitation link from your friend's current arena, or paste its ID into Play with friends. An arena may have filled up or closed since the invitation was shared.
Do skins make my character stronger?
No. Skins change your look and share the same gameplay dimensions. Your mass and actions determine what you can do in a match.
What happens after I am eaten?
Use the free Respawn option to start again, or return to the main menu. A new life starts smaller, giving you another chance to grow.
Tell us what happened
Include your device, browser and the steps to reproduce a problem. Contact Support is available in the game menu.