For more than a decade, if a game ran in your browser, it almost certainly ran on Adobe Flash. Then mobile devices arrived, Flash did not follow them, and Adobe ended support for the plug-in on 31 December 2020. Developers who wanted their games to survive had one realistic option: rebuild them with HTML5 and the web technologies around it.
What HTML5 brought to games
HTML5 is not a single feature but a family of standards that, together, replaced what Flash used to do. The most important for games are:
- Canvas, a drawable area for 2D graphics, sprites and animation.
- WebGL, which gives the browser access to the graphics card for 3D and fast 2D rendering.
- The Web Audio API, for layered sound effects and music with precise timing.
- Touch and pointer events, so the same game works with a mouse or a finger.
Because all of this runs natively, players no longer need to install or update a plug-in. The game simply loads.
One codebase, every screen
The biggest win was portability. A Flash game ran on desktops only; an HTML5 game can run on a laptop, a tablet and a phone from the same code. Developers use responsive layouts to rearrange buttons and reels for portrait or landscape, and they compress images and audio so games load quickly on mobile networks. Frameworks such as Phaser and PixiJS made the transition easier by providing ready-made tools for sprites, physics and input.
A case study: online pokies
Few game types show the shift as clearly as slot machines, known in Australia as pokies. Early online slots were classic Flash files that often refused to run on phones. Today, studios design them for mobile first, using Canvas or WebGL for spinning reels and HTML5 audio for sound. Australian players reading guides such as Casino Bros Australia will notice that mobile compatibility is now treated as a basic requirement rather than a bonus feature. These games are for adults 18+ only, and anyone playing should set limits and play responsibly, but from a technical point of view they are a neat example of how far HTML5 has come.
What developers still have to watch
HTML5 is powerful, but it is not magic. Performance varies between devices, so heavy animations need testing on older phones. Browsers can pause audio until the user interacts with the page, which affects how a game starts. And because the code runs in the open, anything sensitive, such as scoring or game outcomes in real-money products, has to be handled on the server, not in the browser.
The end of Flash looked like a loss at the time. In practice, it pushed games onto open standards that work almost everywhere, and the web is better for it.