🎮 KAPLAY.js — A JavaScript & TypeScript Game Library

KAPLAY is the fun-first, 2D game library for JavaScript and TypeScript. It’s made to feel like a game while you're making games. Simple. Fast. Powerful.

✨ Whether you’re a beginner or an experienced dev, KAPLAY comes with its own web-based editor — the KAPLAYGROUND — so you can try code instantly, and learn with more than 90 examples!

🎲 Quick Overview

// Start a game
kaplay({
    background: "#6d80fa",
});

// Load an image
loadSprite("bean", "https://play.kaplayjs.com/bean.png");

// Add a sprite to the scene
add([
    sprite("bean"), // it renders as a sprite
]);

Game objects are composed from simple, powerful components:

// Add a Game Obj to the scene from a list of components
const player = add([
    rect(40, 40), // it renders as a rectangle
    pos(100, 200), // it has a position (coordinates)
    area(), // it has a collider
    body(), // it is a physical body which will respond to physics
    health(8), // it has 8 health points
    // Give it tags for easier group behaviors
    "friendly",
    // Give plain objects fields for associated data
    {
        dir: vec2(-1, 0),
        dead: false,
        speed: 240,
    },
]);

Blocky imperative syntax for describing behaviors

// .onCollide() comes from "area" component
player.onCollide("enemy", () => {
    // .hp comes from "health" component
    player.hp--;
});

// check fall death
player.onUpdate(() => {
    if (player.pos.y >= height()) {
        destroy(player);
    }
});

// All objects with tag "enemy" will move to the left
onUpdate("enemy", (enemy) => {
    enemy.move(-400, 0);
});

// move up 100 pixels per second every frame when "w" key is held down
onKeyDown("w", () => {
    player.move(0, 100);
});

🖥️ Installation

🚀 Using create-kaplay

The fastest way to get started:

npx create-kaplay my-game

Then open http://localhost:5173 and edit src/game.js.

📦 Install with package manager

npm install kaplay

yarn add kaplay

pnpm add kaplay

bun add kaplay

You will need a bundler like Vite or ESBuild to use KAPLAY in your project. Learn how to setup ESbuild here.

🌐 Use in Browser

Include via CDN:

<script src="https://unpkg.com/kaplay@3001.0.12/dist/kaplay.js"></script>

📜 TypeScript Global Types

If you're using TypeScript, you used create-kaplay or installed with a package manager and you want global types, you can load them using the following directive:

import "kaplay/global";

vec2(10, 10); // typed!

But it's recommended to use tsconfig.json to include the types:

{
  "compilerOptions": {
    "types": ["./node_modules/kaplay/dist/declaration/global.d.ts"]
  }
}

Warning

If you are publishing a game (and not testing/learning) maybe you don't want to use globals, see why.

You can also use all KAPLAY source types importing them:

import type { TextCompOpt } from "kaplay"
import type * as KA from "kaplay" // if you prefer a namespace-like import

interface MyTextCompOpt extends KA.TextCompOpt {
  fallback: string;
}

📚 Resources

📖 Docs

• KAPLAY Official Docs
• KAPLAYGROUND

📺 Tutorials

• 🎥 KAPLAY Library Crash Course by JSLegend ⚔️
• 📖 Learn JavaScript basics and KAPLAY to make games quickly

💬 Community

• Discord Server
• GitHub Discussions
• Twitter/X
• BlueSky
• Mastodon

🎮 Games

Collections of games made with KAPLAY, selected by KAPLAY:

• Itch.io
• Newgrounds.com

🙌 Credits

KAPLAY is an open-source project, maintained by the KAPLAY Team and core contributors and with the support of many other amazing contributors.

🏆 Recognitions

• Thanks to mulfok for the awesome mulfok32 color palette, used in KAPLAY sprites and art
• Thanks to Pixabay for the great burp sound, used in burp() function
• Thanks to Kenney for all used assets for examples
  • Impact Sound Pack
  • 1-Bit Platformer Pack
• Thanks to abrudz for the amazing APL386 font
• Thanks to Polyducks for the amazing kitchen sink font font
• Thanks to 0x72 for the amazing Dungeon Tileset
• Thanks to @Minamotion for the tiny character sprite used in some of the tests