How HTML5 Games Work: A Developer-Friendly Explainer

If you've played a game on BentoTiles, you've played an HTML5 game. But what does that actually mean? How does a game that fits in a browser tab deliver graphics, sound, physics, and interactivity - all without requiring you to install anything?

This article breaks down how modern browser games work, from the technologies that power them to the way they're packaged, hosted, and delivered to your screen.

The Foundation: HTML, CSS, and JavaScript

Every HTML5 game is, at its core, a web page. It uses the same three fundamental technologies that power every website you've ever visited:

• HTML structures the page - defining elements like the game canvas.
• CSS handles visual styling and layout.
• JavaScript is the engine that makes everything move, respond, and behave.

The breakthrough that enabled modern browser gaming was the element, introduced with HTML5. The canvas is essentially a bitmap drawing surface that JavaScript can paint on, pixel by pixel, at up to 60 frames per second. Combined with the Web Audio API for sound, the Pointer Lock API for mouse control, and the Gamepad API for controller support, the browser became a legitimate gaming platform.

The Graphics Pipeline

2D Canvas Games

Most casual HTML5 games use the 2D canvas rendering context (CanvasRenderingContext2D). Every frame, the JavaScript engine:

1. Clears the canvas
2. Calculates the new position of every game object
3. Draws each object to the canvas using draw commands (fillRect, drawImage, arc, etc.)
4. Repeats this 60 times per second using requestAnimationFrame

Libraries like Phaser abstract this process, giving developers a sprite system, a physics engine, a tween system, and an asset loader built on top of the raw canvas.

WebGL Games

For more visually demanding games - those with 3D graphics, real-time lighting, or complex particle systems - developers use WebGL, a JavaScript binding to the OpenGL ES graphics API. WebGL allows the browser to send drawing commands directly to the device's GPU, enabling performance on par with native applications.

Frameworks like Three.js, Babylon.js, and PlayCanvas build on top of WebGL to make 3D game development accessible without writing raw shader code.

Physics and Game Logic

Real games need physics. Objects need to fall, bounce, collide, and slide in ways that feel natural. Most HTML5 game developers use dedicated physics libraries:

• Matter.js - a popular 2D rigid body physics engine
• Box2D - a port of the legendary C++ physics engine, used in countless mobile and desktop games
• Rapier - a modern, high-performance physics engine with a WebAssembly build for near-native speed

Game logic - the rules, win conditions, AI behaviour, progression systems - lives entirely in JavaScript. Well-structured game code separates the "update" step (advancing the game state) from the "render" step (drawing the current state to screen).

Audio

The Web Audio API gives developers granular control over sound. Games can:

• Load and play music and sound effects
• Spatialise audio (make sounds louder when the source is nearby)
• Apply real-time filters and effects
• Synchronise audio to gameplay events precisely

For simpler use cases, the element combined with the Audio() constructor handles basic sound playback with minimal code.

Packaging and Distribution

HTML5 games are typically distributed as a folder of files: an index.html entry point, JavaScript files, assets (images, audio, fonts), and sometimes a service worker for offline support.

When you submit a game to BentoTiles, you package this folder as a ZIP archive. We extract the files, upload them to Cloudflare R2 (our object storage), and serve the game from a dedicated domain. The game loads inside an