Combat Lab

Combat Lab is a browser version of Halo: Combat Evolved, Bungie's 2001 Xbox shooter. Mitchell Hynes hosts and maintains it, and it is built on the community decompilation of the game, compiled to WebAssembly. It covers the campaign and online multiplayer, with 13 maps, six game types and private invite rooms listed at 128 players. It includes no Halo game data, so you load an image of your own disc.

How to play

1. Click Choose XISO and pick an .iso or .xiso image of a disc you own. The page says it is processed locally and stays in your browser. Click the game once it loads to capture the mouse.
2. For online play, pick Play online, enter a name (up to 11 characters) and armor color, choose a map and game type, and create a private room. Share the invite link. Play is peer-to-peer when possible, and a human check runs first.
3. Keyboard and mouse: WASD to move, mouse to aim, Space for A, left mouse button for the right trigger, right mouse button or G for the left trigger, Esc for Start.

What you need

• Browser: the source repository asks for a current desktop browser with WebGL 2, WebAssembly threads, WebRTC and cross-origin isolation, and recommends Chrome.
• Input: keyboard and mouse, or a controller. Hynes has said the web build runs poorly on phones.
• Files: an Xbox disc image of Halo: Combat Evolved from your own copy.

Good to know

• Hynes has called the 128-player scale untested, and early reports found multiplayer less reliable than the campaign.
• It launched on September 29, 2026 under the Halo name and at first needed no disc image; since October 2 it has required your own, so older articles may be out of date. It became Combat Lab on October 19, and the old address redirects.
• The page says the upstream project, OpenCE, does not operate or support it. OpenCE has its own browser version at halocombatevolved.com.