Game Setup and Config

How to create a Phaser.Game instance with the right GameConfig options for renderer, scaling, pixel art, FPS, and canvas placement.

Key source paths: src/core/Game.js, src/core/Config.js, src/core/typedefs/GameConfig.js, src/const.js, src/scale/const/ Related skills: ../scenes/SKILL.md, ../loading-assets/SKILL.md, ../scale-and-responsive/SKILL.md

Quick Start

The simplest possible Phaser 4 game -- a single scene with the default 1024×768 canvas:

class MyScene extends Phaser.Scene {
    preload() {
        this.load.image('logo', 'assets/logo.png');
    }

    create() {
        this.add.image(400, 300, 'logo');
    }
}

const config = {
    type: Phaser.AUTO,
    scene: MyScene
};

const game = new Phaser.Game(config);

new Phaser.Game(config) triggers the entire boot sequence: config parsing (Config), renderer creation, DOM insertion, and the game loop (TimeStep). The game waits for DOMContentLoaded before booting.

Core Concepts

Boot Sequence (src/core/Game.js)

1. new Phaser.Game(config) -- parses config into a Phaser.Core.Config instance.
2. Creates global managers: AnimationManager, TextureManager, CacheManager, InputManager, SceneManager, ScaleManager, SoundManager, TimeStep, PluginManager.
3. Waits for DOMContentLoaded, then calls boot().
4. boot() creates the renderer (CreateRenderer), adds the canvas to the DOM (AddToDOM), prints the debug header, emits BOOT.
5. Once textures are ready (TextureManager emits READY), emits READY then calls start().
6. start() begins the TimeStep loop, sets up the VisibilityHandler, calls config.postBoot.

Config Parsing (src/core/Config.js)

The Config constructor reads a flat GameConfig object and resolves defaults. Some properties can be specified at top level OR nested inside sub-objects (e.g., width can be top-level or under scale.width). The scale sub-object takes priority when both are present.

Render properties can likewise be top-level shortcuts (e.g., pixelArt: true) or nested under render.

Renderer Constants (src/const.js)

Constant	Value	Behavior
Phaser.AUTO	0	WebGL if supported, else falls back to Canvas
Phaser.CANVAS	1	Force Canvas renderer
Phaser.WEBGL	2	Force WebGL -- no fallback if unsupported
Phaser.HEADLESS	3	No renderer -- DOM still required. For unit testing only

Set via config.type. Default is Phaser.AUTO.

Common Patterns

Pixel Art Game

When pixelArt is true, Config automatically sets antialias: false, antialiasGL: false, and roundPixels: true.

const config = {
    type: Phaser.AUTO,
    width: 320,
    height: 240,
    pixelArt: true,
    scale: {
        mode: Phaser.Scale.FIT,
        autoCenter: Phaser.Scale.CENTER_BOTH,
        zoom: Phaser.Scale.ZOOM_2X
    },
    scene: MyScene
};

Smooth Pixel Art (WebGL only)

Preserves blocky pixels but smooths edges between them when scaled up:

const config = {
    type: Phaser.WEBGL,
    width: 320,
    height: 240,
    smoothPixelArt: true,
    scene: MyScene
};

When smoothPixelArt is true, Config sets antialias: true, antialiasGL: true, and pixelArt: false.

Full-Window Responsive Game

const config = {
    type: Phaser.AUTO,
    scale: {
        mode: Phaser.Scale.RESIZE,
        parent: 'game-container',
        width: '100%',
        height: '100%'
    },
    scene: MyScene
};

Fixed Aspect Ratio with FIT

const config = {
    type: Phaser.AUTO,
    scale: {
        mode: Phaser.Scale.FIT,
        parent: 'game-container',
        autoCenter: Phaser.Scale.CENTER_BOTH,
        width: 1280,
        height: 720,
        min: { width: 640, height: 360 },
        max: { width: 1920, height: 1080 }
    },
    backgroundColor: '#2d2d2d',
    scene: MyScene
};

Custom FPS Limit

const config = {
    type: Phaser.AUTO,
    width: 800,
    height: 600,
    fps: {
        target: 60,
        limit: 30,
        forceSetTimeOut: false,
        smoothStep: true
    },
    scene: MyScene
};

Transparent Canvas Over HTML

const config = {
    type: Phaser.AUTO,
    width: 800,
    height: 600,
    transparent: true,
    parent: 'game-container',
    scene: MyScene
};

When transparent is true, backgroundColor is forced to 0x000000 with alpha 0.

Pre-existing Canvas Element

const canvas = document.getElementById('my-canvas');

const config = {
    type: Phaser.WEBGL,
    canvas: canvas,
    width: 800,
    height: 600,
    scene: MyScene
};

Multiple Scenes

const config = {
    type: Phaser.AUTO,
    width: 800,
    height: 600,
    scene: [BootScene, PreloadScene, MenuScene, GameScene],
    physics: {
        default: 'arcade',
        arcade: { gravity: { y: 300 } }
    }
};

Only the first scene starts automatically. Others start only if they have { active: true } in their scene config. See ../scenes/SKILL.md.

Boot Callbacks

const config = {
    type: Phaser.AUTO,
    width: 800,
    height: 600,
    callbacks: {
        preBoot: function (game) {
            // Runs before Phaser boots. Game systems not yet available.
        },
        postBoot: function (game) {
            // Runs after boot. All systems ready, game loop starting.
        }
    },
    scene: MyScene
};

Disabling Input Subsystems

const config = {
    type: Phaser.AUTO,
    width: 800,
    height: 600,
    input: {
        keyboard: true,
        mouse: true,
        touch: false,
        gamepad: false,
        activePointers: 1,
        windowEvents: true
    },
    disableContextMenu: true,
    scene: MyScene
};

Configuration Reference

Top-Level GameConfig Properties

Property	Type	Default	Description
type	number	Phaser.AUTO (0)	Renderer: AUTO, CANVAS, WEBGL, or HEADLESS
width	number|string	1024	Game width in pixels (or '100%'). Overridden by scale.width
height	number|string	768	Game height in pixels (or '100%'). Overridden by scale.height
zoom	number	1	Canvas zoom multiplier. Overridden by scale.zoom
parent	HTMLElement|string|null	undefined	DOM element or id for canvas. undefined = document body. null = no parent
canvas	HTMLCanvasElement	null	Provide your own canvas element
context	CanvasRenderingContext2D|WebGLRenderingContext	null	Provide your own rendering context
canvasStyle	string	null	CSS styles applied to the canvas element
customEnvironment	boolean	false	Skip feature detection for non-browser environments. renderType cannot be AUTO if true
scene	SceneType|SceneType[]	null	Scene class (extends Phaser.Scene) or array of scene classes
seed	string[]	[random]	Seed for Phaser.Math.RND
title	string	''	Game title shown in console banner
url	string	'https://phaser.io/...'	Game URL shown in console banner
version	string	''	Game version shown in console banner
autoFocus	boolean	true	Auto-focus window on boot and mousedown
stableSort	number|boolean	-1	-1 = auto-detect, 0/false = built-in stable sort, 1/true = rely on native ES2019 sort
disableContextMenu	boolean	false	Disable right-click context menu
backgroundColor	string|number	0x000000	Canvas background color. Accepts hex number, CSS string, or color object
banner	boolean|BannerConfig	(shown)	false to hide console banner entirely

scale (Phaser.Types.Core.ScaleConfig)

Property	Type	Default	Description
width	number|string	1024	Base game width
height	number|string	768	Base game height
zoom	number	1	Zoom multiplier. Use constants: NO_ZOOM (1), ZOOM_2X (2), ZOOM_4X (4), MAX_ZOOM (-1)
parent	HTMLElement|string	undefined	DOM parent for the canvas
mode	number	Phaser.Scale.NONE (0)	Scale mode (see table below)
expandParent	boolean	true	Allow adjusting parent CSS height to 100%
autoRound	boolean	false	Round display/style sizes for performance
autoCenter	number	NO_CENTER (0)	Canvas centering mode (see table below)
resizeInterval	number	500	Milliseconds between browser size checks
fullscreenTarget	HTMLElement|string	null	Element for fullscreen mode
min	{width, height}	{0, 0}	Minimum canvas dimensions
max	{width, height}	{0, 0}	Maximum canvas dimensions (0 = no limit)
snap	{width, height}	{0, 0}	Snap canvas size to multiples

Scale Modes (src/scale/const/SCALE_MODE_CONST.js)

Constant	Value	Behavior
Phaser.Scale.NONE	0	No scaling. Canvas stays at config size
Phaser.Scale.WIDTH_CONTROLS_HEIGHT	1	Height adjusts based on width
Phaser.Scale.HEIGHT_CONTROLS_WIDTH	2	Width adjusts based on height
Phaser.Scale.FIT	3	Fit inside parent keeping aspect ratio (letterboxing)
Phaser.Scale.ENVELOP	4	Cover parent keeping aspect ratio (may overflow)
Phaser.Scale.RESIZE	5	Canvas resizes to fill parent, ignoring aspect ratio
Phaser.Scale.EXPAND	6	Like RESIZE for visible area + FIT for canvas scale

Center Modes (src/scale/const/CENTER_CONST.js)

Constant	Value
Phaser.Scale.NO_CENTER	0
Phaser.Scale.CENTER_BOTH	1
Phaser.Scale.CENTER_HORIZONTALLY	2
Phaser.Scale.CENTER_VERTICALLY	3

Zoom Constants (src/scale/const/ZOOM_CONST.js)

Constant	Value	Behavior
Phaser.Scale.NO_ZOOM	1	No zoom
Phaser.Scale.ZOOM_2X	2	2x zoom
Phaser.Scale.ZOOM_4X	4	4x zoom
Phaser.Scale.MAX_ZOOM	-1	Max integer zoom that fits in parent

render (Phaser.Types.Core.RenderConfig)

These can be set at the top level OR nested under render. The render sub-object takes priority.

Property	Type	Default	Description
antialias	boolean	true	Linear interpolation for scaled/rotated textures
antialiasGL	boolean	true	Antialias on WebGL context creation
pixelArt	boolean	false	Sets antialias: false, roundPixels: true automatically
smoothPixelArt	boolean	false	WebGL only. Blocky pixels with smooth edges
roundPixels	boolean	false	Snap texture-based objects to integer positions
transparent	boolean	false	Transparent canvas background
clearBeforeRender	boolean	true	Clear canvas each frame
preserveDrawingBuffer	boolean	false	Preserve WebGL buffers between frames
premultipliedAlpha	boolean	true	Pre-multiplied alpha in WebGL drawing buffer
desynchronized	boolean	false	Desynchronized rendering context
failIfMajorPerformanceCaveat	boolean	false	Abort WebGL if browser reports poor performance
powerPreference	string	'default'	'high-performance', 'low-power', or 'default'
batchSize	number	16384	Max quads per WebGL batch
maxTextures	number	-1	Max GPU textures. -1 = use all available
maxLights	number	10	Max lights visible per camera
autoMobileTextures	boolean	true	Restrict to 1 texture per batch on iOS/Android
selfShadow	boolean	false	Self-shadowing on lit textured objects
pathDetailThreshold	number	1	Point-combining threshold for Graphics WebGL paths
skipUnreadyShaders	boolean	false	Skip drawing objects whose shader is still compiling
mipmapFilter	string	''	Mipmap filter: 'NEAREST', 'LINEAR', 'NEAREST_MIPMAP_NEAREST', etc.
renderNodes	object	{}	Custom render nodes for WebGL renderer

fps (Phaser.Types.Core.FPSConfig)

Property	Type	Default	Description
min	number	5	Minimum acceptable FPS
target	number	60	Target FPS (informational, does not enforce)
limit	number	0	Enforce max FPS. 0 = no limit
forceSetTimeOut	boolean	false	Use setTimeout instead of requestAnimationFrame
deltaHistory	number	10	Frames to average for delta smoothing
panicMax	number	120	Frames before trusting delta again after a panic
smoothStep	boolean	true	Apply delta smoothing

Other Sub-Configs

Sub-Config Key	Type	Source
callbacks	CallbacksConfig	src/core/typedefs/CallbacksConfig.js
dom	DOMContainerConfig	src/core/typedefs/DOMContainerConfig.js
input	InputConfig	src/core/typedefs/InputConfig.js
loader	LoaderConfig	src/core/typedefs/LoaderConfig.js
physics	PhysicsConfig	src/core/typedefs/PhysicsConfig.js
plugins	PluginObject|PluginObjectItem[]	src/core/typedefs/PluginObject.js
audio	AudioConfig	src/core/typedefs/AudioConfig.js
images	ImagesConfig	src/core/typedefs/ImagesConfig.js

Game Lifecycle, Pause/Resume, and Destroy

Game Lifecycle Events

Listen on game.events (or this.game.events from a Scene) for visibility and focus changes:

game.events.on('blur', () => { /* tab lost focus */ });
game.events.on('focus', () => { /* tab regained focus */ });
game.events.on('hidden', () => { /* Page Visibility API: page hidden */ });
game.events.on('visible', () => { /* Page Visibility API: page visible */ });
game.events.on('pause', () => { /* game.pause() was called */ });
game.events.on('resume', () => { /* game.resume() was called */ });

Use named constants: Phaser.Core.Events.BLUR, FOCUS, HIDDEN, VISIBLE, PAUSE, RESUME.

Pause and Resume

// Pause the entire game loop (rendering and updates stop)
game.pause();

// Resume the game loop
game.resume();

// Check if the game is currently paused
if (game.isPaused) {
    // game loop is not running
}

Destroying the Game

// Remove the canvas from the DOM and clean up
game.destroy(true);

// Full cleanup -- pass noReturn=true if you will NEVER create another Phaser instance
// This allows the framework to release additional internal references
game.destroy(true, true);

destroy(removeCanvas, noReturn) is asynchronous -- it flags the game for destruction on the next frame. Listen for Phaser.Core.Events.DESTROY to react to completion.

Global Game Members

The Game instance exposes key managers as properties, accessible from any Scene via this.game:

Property	Type	Description
game.config	Phaser.Core.Config	Parsed GameConfig (read-only after boot)
game.scene	SceneManager	Start, stop, switch, and manage all scenes
game.registry	DataManager	Shared data store across all scenes
game.anims	AnimationManager	Global animation definitions
game.cache	CacheManager	Stores loaded non-texture assets (JSON, XML, etc.)
game.textures	TextureManager	Stores all loaded textures and sprite sheets
game.sound	SoundManager	Global sound playback manager

// Example: access the registry from any scene
this.game.registry.set('highScore', 9999);

// Example: access the scene manager
this.game.scene.start('MenuScene');

Gotchas and Common Mistakes

1. scale vs top-level config. width, height, zoom, and parent can be set at the top level or inside scale. The scale sub-object values take priority. Avoid setting both to prevent confusion.

2. Phaser.WEBGL has no fallback. Unlike AUTO, using Phaser.WEBGL directly will not fall back to Canvas if WebGL is unavailable. The game will fail silently.

3. parent: null vs parent: undefined. undefined (or omitted) appends the canvas to document.body. null means Phaser will not add the canvas to the DOM at all -- you must do it yourself.

4. transparent overrides backgroundColor. When transparent: true, the background color is forced to rgba(0,0,0,0) regardless of what you set.

5. fps.target does not enforce frame rate. It is advisory only. Use fps.limit to actually cap the frame rate. The browser's display refresh rate is always the upper bound.

6. fps.limit only slows down, never speeds up. Setting limit: 120 on a 60Hz display still results in 60 FPS.

7. DOM Container requires a parent. Setting dom.createContainer: true without providing a parent element will not work.

8. smoothPixelArt is WebGL-only. It has no effect with the Canvas renderer.

9. window.FORCE_WEBGL and window.FORCE_CANVAS. Config.js checks for these globals at the end of parsing and will override the type setting. This is intended for development/testing.

10. Game.destroy() is asynchronous. It flags the game for destruction on the next frame. Listen for the DESTROY event to react to completion. Pass noReturn: true only if you will never create another Phaser instance on the same page.

v4 Changes from v3

• Default dimensions changed: Width defaults to 1024 (was 800), height to 768 (was 600).
• EXPAND scale mode added: Phaser.Scale.EXPAND (value 6) is new -- combines RESIZE visible area behavior with FIT canvas scaling.
• Loader maxRetries default: loader.maxRetries defaults to 2 (was 0 in early v3).
• smoothPixelArt option: New WebGL-only rendering mode that smooths edges between blocky pixels.
• renderNodes config: New render.renderNodes property for custom WebGL render node registration.
• skipUnreadyShaders: New option for parallel shader compilation to prevent stutter.
• pathDetailThreshold: New config for Graphics WebGL path point combining.

Source File Map

Concept	File
Game class / boot sequence	src/core/Game.js
Config parsing / all defaults	src/core/Config.js
GameConfig typedef	src/core/typedefs/GameConfig.js
Renderer constants (AUTO, WEBGL, CANVAS, HEADLESS)	src/const.js
FPSConfig typedef	src/core/typedefs/FPSConfig.js
RenderConfig typedef	src/core/typedefs/RenderConfig.js
ScaleConfig typedef	src/core/typedefs/ScaleConfig.js
Scale mode constants	src/scale/const/SCALE_MODE_CONST.js
Center constants	src/scale/const/CENTER_CONST.js
Zoom constants	src/scale/const/ZOOM_CONST.js
TimeStep (game loop)	src/core/TimeStep.js
Renderer creation	src/core/CreateRenderer.js
ScaleManager	src/scale/ScaleManager.js
CallbacksConfig typedef	src/core/typedefs/CallbacksConfig.js
DOMContainerConfig typedef	src/core/typedefs/DOMContainerConfig.js
InputConfig typedef	src/core/typedefs/InputConfig.js
LoaderConfig typedef	src/core/typedefs/LoaderConfig.js
All core typedefs	src/core/typedefs/