The short answer
The Xbox One has two HDMI ports with different jobs:
- HDMI OUT goes to your TV or AV receiver.
- HDMI IN takes the output of another HDMI device, such as a cable or satellite box.
Microsoft's support page notes that the Xbox Series X|S has no HDMI in port, so you can't connect a cable or satellite receiver to it. The One was built differently on purpose.
Why Microsoft built it
In 2013, Microsoft's launch blog post described the Xbox One as the only games and entertainment system that enables HDMI pass through. The idea was a single living-room box that handled games, apps and live TV. In that post, Microsoft also introduced OneGuide, the console's electronic program guide.
The pass-through port was the hardware half of that plan, and OneGuide was the software half. In practice, the Xbox One needed a cable or satellite box connected through the HDMI pass-through to use voice commands and features like OneGuide.
How the connection works
PCWorld's setup walkthrough describes the basic arrangement. You unplug the HDMI cable that runs from your set-top box to your TV or AV receiver and plug it into the Xbox One's HDMI input. The ports are clearly labeled on the back of the console. Afterward, check that the Xbox's HDMI output is still connected to your TV.
The same approach works for other HDMI sources. A GameSpew guide covers using the port with another console:
- Plug one end of an HDMI cable into the other device's HDMI out socket and the other end into the Xbox One's HDMI In socket.
- Turn on the other device, then launch OneGuide on the Xbox One.
- Follow the on-screen instructions. You only need to set up OneGuide once.
Afterward, the routine is short: turn the Xbox One on, turn the other device on, and launch OneGuide. Per the same guide, the Xbox One has to be fully on to pass the signal through. Sleep mode isn't enough.
The Xbox One doesn't replace the connected device. The external box still supplies its own content, and the console only relays it.
What changed in 2021
Many articles on this topic blur two things together: live TV listings and the HDMI input itself.
- Live TV listings were removed. In March 2021, Microsoft announced that as of May 2021 OneGuide on Xbox One no longer supports live TV listings.
- The HDMI input stayed. Microsoft says you can continue to use OneGuide to view connected HDMI devices or a USB TV tuner. The announcement said OneGuide still works for HDMI pass-through and USB TV tuners, but the on-screen TV listings guide is gone.
So the port wasn't removed from the Xbox One, and it wasn't disabled. What went away was the program guide that sat on top of it. The BGR article calls OneGuide a "glorified HDMI selector" now. That's an informal description, not Microsoft's terminology, but it does reflect what's left.
Where to find OneGuide
A GameSpew update says OneGuide is no longer in the app store but should be accessible from "My games & apps." That guide is from 2019, so I can't confirm it matches every console's current software state. If you can't find OneGuide on your own console, check your installed apps first.
Caveats worth knowing
- Input lag. BGR says the pass-through adds a very small amount of input lag. That's minor for a cable box, but it matters more if you're plugging in a second game console. GameSpew gives the same warning about slight controller lag. I didn't find Microsoft-published latency figures, so treat this as reported experience, not a spec.
- Compatibility varies. A set-top box usually works, but results depend on the source device, region and setup. One tutorial notes that controlling a cable box through OneGuide required a Kinect (for infrared blasting) or an Xbox One S with a built-in IR blaster. That applied to the live TV control features, which no longer exist. Don't assume you can control every external device from the Xbox.
- It's pass-through only. Nothing I found supports claims that the port adds recording, gameplay capture or its own TV service.
A correction on the Series X|S
BGR says the Series X|S has an HDMI ARC/eARC port that works as both input and output. That doesn't match Microsoft's own documentation. Microsoft's support page says the Series X|S does not have an HDMI in port. It advises connecting cable or satellite directly to your TV instead. Xbox's official Series X page also lists a single HDMI 2.1 port. The Series X|S therefore has no dedicated HDMI input to compare with the Xbox One's.
If you miss the port
BGR suggests a separate HDMI selector as the workaround. That's reasonable advice, with one condition: the selector has to support the video specs you actually use. BGR recommends at least HDMI 2.1 and 4K/120Hz support. A selector keeps the console free of added pass-through lag, and it works with a Series X|S, which has no input port at all.
Bottom line
- The extra Xbox One port is an HDMI input for passing another device's picture and sound through the console to your TV.
- OneGuide is the interface for viewing that source.
- Microsoft removed live TV listings in May 2021, but said HDMI pass-through and connected-device viewing remained.
- The Series X|S has no HDMI input, according to Microsoft's own support page.