Halo Infinite isn't getting split-screen co-op, but fans have figured out how to do it anyway

gamesradar.com:

Halo Infinite may not officially have splitscreen co-op but that hasn't stopped players from figuring out how to get up to four couch co-op partners anyway.

Courtesy of a menu glitch and some kind of tech wizardry that quietly blows my mind, players have worked out how to implement local co-op that supports up to four players without impacting cut-scenes or even enemy spawns and behaviors.

As for how you can pull it off? Well, you'll need an Xbox Series S or X, an online friend, and this workaround from @Zeny_IC (opens in new tab), which has been written up by @HaloCreation (opens in new tab):

Whilst, obviously, it's not formally supported and therefore may result in some odd behavior, right now the glitch seems to work like a charm. 

Follow-up on this, here's a quick tutorial on how to play #HaloInfinite Splitscreen Coop using a menu glitch found by @Zeny_IC! (Kinda low effort, but it's 2AM, I'm tired, and it does contain everything you need to know to DIY!