How to Play Agar.io: Controls, Viruses, Splits, and Survival Tips

Agar.io is a multiplayer game in which you control a cell, collect pellets, and absorb player cells that are sufficiently smaller than yours. Larger cells move more slowly, while splitting creates speed and reach at the cost of making each piece vulnerable. A strong run depends on judging size, keeping an escape route, and using splits only when the reward is worth the risk.

Play through the official Agar.io site or official mobile app. Avoid copycat sites and browser extensions that promise extra mass, automation, or unfair advantages.

Basic Agar.io controls

• Move: Point the mouse where the cell should travel.
• Split: Press Space to send half of a cell forward.
• Eject mass: Press W to release a small amount in the cursor's direction.

On mobile, use the corresponding on-screen controls. Test splitting and ejection in open space because both actions reduce the safety of the main cell.

Grow safely at the start

Collect the small food pellets spread around the map and avoid players that can absorb you. At low mass, movement speed is an advantage. Travel through open gaps rather than along a wall where a larger player can limit your escape.

• Scan ahead instead of keeping the pointer directly beside your cell.
• Do not chase one pellet into a cluster of larger players.
• Keep viruses between you and a threatening large cell when possible.
• Move toward less crowded areas until you are large enough to contest player fragments.

Use viruses as cover

Green spiked viruses are obstacles for large cells. A cell that is small enough can move behind or through one, while a sufficiently large cell that consumes a virus breaks into many pieces. This makes a virus useful cover when a much larger opponent is chasing you.

Do not assume every opponent fears a virus. A player with room for more pieces may intentionally use one, and a divided cell can sometimes absorb you from several angles.

Split attacks: powerful but risky

When you split, one part shoots toward the cursor. If that launched piece is large enough to absorb the target, the attack can secure mass quickly. If it misses, the separated pieces have less mass, offer more targets, and cannot immediately recombine.

Before pressing Space, check:

• Is the target clearly small enough for the launched half?
• Is another large player waiting beyond it?
• Will the split send a piece into a wall or virus?
• Can you protect both pieces while they recombine?

Use a single controlled split before attempting multi-split moves. Complex chains are effective only when the size calculation and surrounding space are understood.

Feed a virus to pressure a large cell

Ejected mass can feed a virus. After receiving enough, the virus launches a new virus in the direction it was fed. Skilled players use this to split a nearby large opponent and then absorb the vulnerable pieces.

This tactic consumes your own mass and can help another player if the angle is wrong. Line up the target, check who can collect the resulting pieces, and stop if the opponent moves away.

Manage multiple pieces

Separated cells gradually move together and recombine after a delay. Larger pieces generally take longer. During that period:

• Keep small pieces behind the largest piece when approaching danger.
• Avoid narrow corners where the group cannot change direction.
• Collect pellets with the smaller pieces without separating the formation too far.
• Do not eject mass to strangers unless it serves a clear team-mode objective.

Cornering and map awareness

The arena has boundaries. You can pressure a smaller player toward an edge, but the same position is dangerous if a larger cell approaches from behind. Move diagonally so the target's options shrink while your own route remains open.

High scores come from selective aggression. Absorb safe targets, use viruses to control space, and decline a split when the outcome depends on guessing. Surviving for another minute usually creates more opportunities than forcing one uncertain attack.