Answers for developers, publishers and site owners on monetizing and distributing web games.
337 posts
A cross-device save writes progress to a platform's cloud storage (keyed to the logged-in player) instead of the browser's local storage, so the same save loads on any device. The game calls a load before gameplay starts and a save on meaningful state changes, treating missing data as defaults rather than an error.
Use localStorage for small synchronous flags (settings, a single save slug) under a few hundred KB. Switch to IndexedDB when you store larger structured data, binary assets, many records, or need async, non-blocking reads and writes - for example level data, asset caches or multiple save slots.
For a browser game, use the Web Storage API (localStorage) for small key-value saves or IndexedDB for larger structured data. If the game runs on multiple platforms, route saves through a storage abstraction so the same code can write to a platform's cloud save instead of only the browser.
Load a minimal boot bundle first (menu, first-level assets), then fetch remaining scenes, textures and audio in the background using dynamic imports and an asset manifest. Split code by scene/route, defer non-critical JS, and preload the next level while the player is on the current one.
Reduce draw calls by batching sprites/meshes that share a material, packing textures into atlases so fewer bind calls happen, sorting the render queue by texture/shader before draw order, and avoiding per-object uniform or texture switches inside the render loop.
Open DevTools > Performance, record while the game runs, then read the flame chart for long tasks, scripting vs rendering vs painting time, and dropped frames. Fix the largest bar first, re-record, and repeat. Use Memory and Rendering panels for leaks and paint issues.
Listen for visibilitychange (or the platform SDK's pause event) and toggle a single isPaused flag that stops your update loop, timers and audio, then resumes them on visible/resume. Audio needs an explicit resume call because browsers don't restart it automatically.
Cap the device pixel ratio, batch draw calls, keep textures power-of-two and compressed, avoid per-frame allocations, and use WebGL rather than full 2D canvas redraws for anything animated. Test on real mid-tier phones, not desktop dev tools.
Use Pointer Events (pointerdown/move/up) on a fixed-position overlay layer, track a base and knob element for the joystick, normalize the drag vector, and only render the controls when you detect a touch or mobile device so desktop users keep keyboard/mouse input.
Set the canvas's CSS size to fill its container, then set its actual width/height (backing store) to CSS size times devicePixelRatio for sharpness. Listen for resize and orientationchange, recompute a scale factor, and rescale your game's internal coordinate system on every change.