Wave Battler Online Co-op: Play With a Friend Using a Room Code

Wave Battler has online co-op for two players, right in the browser. One of you hosts, the other types a 6-digit room code, and you play the same run together. There is nothing to install and no sign-up needed. It is one of the easiest ways to play a free browser game with a friend who is somewhere else.

How to start an online co-op game

1. 1

   Open Online co-op

   On the main menu at wavebattler.com/play, choose Online co-op.

2. 2

   Host a game

   One player picks Host a game and gets a 6-digit code.

3. 3

   Send the code

   Send it any way you like: a text, WhatsApp, a call.

4. 4

   Join a game

   The other player picks Join a game and types the code on the game's own number pad. Keys, a controller or a thumb all work.

5. 5

   Host starts the run

   The host picks the mode, the world and the difficulty, then starts.

There is no game server in the middle. The host's browser runs the world and the two browsers talk directly; when a network will not allow that, a relay carries the game instead. If you cannot connect, use Check my connection on the same screen. Strict networks (school, office) and phone data are the usual cause, so try both on home Wi-Fi. A game holds two players.

Host and joiner

• The host chooses Campaign or Endless, Deep Drift or Neon Grid, and the difficulty. The host's Devil setting counts for both players.
• Each player brings their own skill tree, kit and ability. There is no Loadout step in co-op.
• Skins are not shown in co-op; the two ships keep team colours so you can tell each other apart.
• Pause stops the game for both of you. A phone switching apps or a hidden tab makes the run wait instead of dropping anyone.

Playing co-op on a phone

Phones can host or join. Hold the phone sideways: the joystick appears under your left thumb, with Dash and Ability on the right. In co-op on a phone, your teammate's health shows under their name in the world, which keeps the corner of the screen clear.

How co-op changes the waves

Two heroes deal a lot more damage than one, so the world grows to match.

• Waves have 50% more enemies.
• Every enemy's health is multiplied by wave: ×1.8 at wave 1, ×2.2 at wave 10, ×2.6 at 20, ×3.0 at 30 and ×3.2 at 40. Mini-bosses get another ×1.35 on top.
• Boss health is set from the team's measured damage, so a boss lasts about as long for two as it does for one, and it wears an extra 15% shell.
• Special waves are 25% bigger, and the Snake Storm brings 3 more snakes.
• Coins: each hero is paid in full, and coins either of you picks up pay you both.

The Hard and Brutal co-op squeeze

On Hard, Brutal and Impossible, co-op adds a second climb on top of everything above. It starts at wave 15 on Hard and at wave 8 on Brutal and Impossible, and grows until wave 40.

Tips for two players

• Pick each other up. When a hero goes down, the other stands next to them for about 2.5 seconds. They come back at 35% health and cannot be hurt for a moment.
• Clearing the wave also revives. A downed hero stands back up at half health when the wave is cleared.
• Extra lives still work. One saves you from going down at all.
• Split the jobs. You each have your own coins, cards and shop. One boss killer (Focus Fire, Giant Slayer) and one crowd clearer (Spreadfire, Overkill) cover each other well.
• Talk before the Devil. You take turns choosing, and the deal binds both of you, price and reward.
• Stay close on boss waves. Bosses are sized for the team, so a lone survivor faces a fight built for two. Keep each other in reach for a quick revive.

Builds are covered in the builds guide, and the bosses you will meet in the boss guide.

World leaderboards

There are 20 boards: solo or co-op, Campaign or Endless, and each of the five difficulties. Each board keeps your best run. A score is waves cleared ×1000, plus kills ×10, best combo ×30 and coins earned, multiplied by the difficulty bonus (×1.2 on Normal up to ×2.0 on Impossible).

Signed out, a new best goes up under a nickname, asked for on the end screen the first time. Sign in later with Google or email and this device's scores move onto your account, which also syncs your tree and bests across devices.