Play Command & Conquer: Generals Zero Hour in Your Browser

About Command & Conquer: Generals Zero Hour

Zero Hour is the expansion pack for Command & Conquer: Generals, the 2003 real-time strategy game. EA Los Angeles developed it and EA Games published it for Windows, releasing it in North America on September 22, 2003, followed by Australia and Europe a few days later. A Mac OS X version, ported by i5works and published by Aspyr, arrived in February 2005. John Salwitz directed the expansion, Nathan James Levites is credited as designer, and Bill Brown and Mikael Sandgren wrote the music. Like Generals, it runs on EA’s SAGE engine.

The expansion gave each side new abilities and units and added a mode of play called Generals’ Challenge. It also brought a long list of other changes, new features and fixes for bugs and glitches. Both single-player and multiplayer are part of the original game.

How it runs in your browser

This version isn’t emulated. In February 2025, Electronic Arts published the source code of Generals and Zero Hour under the GPL v3 licence. The release covered the code only: the art, audio and maps were not open-sourced. The Generals-WebAssembly project took that code and ported it to WebAssembly, and adapted the original Direct3D renderer to WebGL 2. The result is the actual game engine running natively in the browser, rather than a virtual Windows PC running the old executable. That sets it apart from most DOS.Zone listings, which emulate a whole computer through js-dos.

Pressing Play opens the game on dos.zone in a new tab. You don’t install anything or create an account. Game data is downloaded as it’s needed and cached locally with OPFS, the browser’s private file storage, so DOS.Zone says later launches are significantly faster than the first. Because the game’s art, audio and maps weren’t part of the open-source release, this remains an unofficial build rather than anything EA put out.

DOS.Zone says the port keeps Zero Hour’s factions, units, campaigns and skirmish battles. Online multiplayer isn’t listed for this version, so plan on playing against the computer.

Controls and devices

Use a keyboard and mouse, as on the PC original. The host’s page doesn’t list a key layout, so check the game’s own menus for the controls. Since the renderer depends on WebGL 2, a current desktop browser is the safe choice.

Phones and tablets haven’t been checked. A real-time strategy game with this much on screen is hard to manage without a mouse, so plan on a desktop or laptop.

Who it’s for

It suits Zero Hour players who want a skirmish on a computer without the original installed, and anyone curious to see EA’s released code running in a browser tab. Players who want the earlier Westwood games can try the 1995 Command & Conquer on DOS.Zone, or the fan remake on our Red Alert 2 page, which adds online matches.