Xbox HDMI 2.1 settings are at the heart of getting 4K, 120fps, HDR, and Variable Refresh Rate working on your Xbox Series X. The console has all the hardware to deliver these features — but they only work when your TV, your cable, and your Xbox settings are all configured correctly. This guide covers every step, including what HDMI 2.1 actually means, what to change on your Xbox, and how to enable the right mode on popular TV brands.
TL;DR
- The Xbox Series X has a single HDMI 2.1 port that supports 4K at 120Hz, VRR, HDR10, and Dolby Vision
- You need an Ultra High Speed HDMI cable and a display with a true HDMI 2.1 (FRL) port — not HDMI 2.1 TMDS
- On the Xbox: enable Allow 4K, Allow 120Hz, Allow HDR10, and Allow Variable Refresh Rate under Settings > General > TV & Display Options > Video Modes
- On your TV: enable Enhanced Mode, HDMI Ultra HD Deep Colour, or the equivalent for the HDMI port you are using
- Check the 4K TV Details screen on your Xbox to confirm everything is working
- Most TVs only have one HDMI 2.1 port — make sure your Xbox is plugged into the right one
What HDMI 2.1 Actually Means for Xbox
HDMI 2.1 is what makes 4K at 120fps possible on Xbox Series X. The older HDMI 2.0 standard maxes out at 18Gbps of bandwidth. That is enough for 4K at 60fps but not for 4K at 120fps with full colour depth. HDMI 2.1 raises the ceiling to 48Gbps, which is the headroom you need for high-bandwidth gaming features.
The Xbox Series X uses a specific HDMI 2.1 signalling method called FRL (Fixed Rate Link). This is the real HDMI 2.1. The console operates at FRL Rate 5, which gives it enough bandwidth for 4K at 120Hz with 10-bit colour and HDR.
There is a catch with TV labelling. Some budget displays are sold as “HDMI 2.1” but actually use TMDS signalling — which is essentially the same bandwidth as HDMI 2.0. These ports cap out at 18Gbps. You will not get 4K at 120fps from them regardless of your settings. When shopping for a display, look for HDMI 2.1 FRL or check the spec sheet for 40Gbps or 48Gbps bandwidth on the HDMI port. Avoid anything labelled “HDMI 2.1 TMDS.”
The Xbox Series X operates at up to 40Gbps over HDMI 2.1, which is enough to support 4K at 120Hz with 10-bit colour at 4:4:4 chroma — the full quality signal.
What the Xbox Series X HDMI 2.1 Port Supports
The Xbox Series X has one HDMI 2.1 port on the back. When paired with a compatible display and cable, it supports:
- 4K at 120Hz — via HDMI 2.1 FRL
- 4K at 60Hz — also works over HDMI 2.0
- 1440p and 1080p at 120Hz — possible over HDMI 2.0 as well
- HDR10 — supported over both HDMI 2.0 and HDMI 2.1
- Dolby Vision for Gaming — supported over both HDMI 2.0 and HDMI 2.1
- Variable Refresh Rate (VRR) — requires HDMI 2.1 FRL or a display with VESA Adaptive Sync/FreeSync over HDMI
- Auto Low Latency Mode (ALLM) — works over HDMI 2.1
One thing worth knowing: the Xbox will automatically detect your TV’s capabilities over the HDMI link. So when you first connect, it reads what your display supports and adjusts accordingly. If features are missing or greyed out in settings, it usually means the TV isn’t reporting support for them — which is often a cable or TV settings issue rather than a hardware limitation.
Xbox HDMI 2.1 Cable — What to Use
The cable that comes in the box with the Xbox Series X is an Ultra High Speed HDMI cable, certified for 48Gbps. Use this. It is the correct cable for HDMI 2.1 and handles everything the console can output.
If you need a replacement or a longer cable, make sure it is labelled Ultra High Speed HDMI — that is the official certification for 48Gbps cables. Cables labelled High Speed or Premium High Speed are HDMI 2.0-era and are limited to 18Gbps. Using the wrong cable will silently cap your output. You may still get a picture but you will not get 4K at 120fps or full colour depth.
Cable length matters too. Ultra High Speed HDMI cables can lose signal integrity at longer lengths. For most gaming setups, 2 metres is fine. Above 3–4 metres, check reviews carefully or consider an active HDMI cable rated for the bandwidth.
TV Setup — How to Enable HDMI 2.1 on Your Display
This is the most commonly skipped step. Even if your TV has HDMI 2.1 ports, they are often in a restricted mode by default. You need to manually enable the enhanced bandwidth mode on the port your Xbox is connected to.
The setting name varies by brand. Here is what to look for:
Samsung
Go to Settings > General > External Device Manager > Input Signal Plus. Enable it on the HDMI port your Xbox uses. On Samsung TVs, only certain ports — often HDMI 4 — are HDMI 2.1. Check your model’s spec sheet to confirm which port to use. Older Samsung models may call this setting HDMI UHD Color under Settings > Picture > Expert Settings.
LG
Go to Settings > All Settings > General > HDMI Ultra HD Deep Colour. Enable it for the port your Xbox is connected to. LG OLEDs from 2019 onwards generally support HDMI 2.1 on multiple ports.
Sony Bravia
Press the Home button, then go to Settings > External Inputs > HDMI Signal Format. Set the relevant port to Enhanced Format. The default is Standard, which limits bandwidth.
Hisense
The setting is called Enhanced Format and is found in the TV’s HDMI input settings. Some Hisense models list it under a Game Zone or picture settings menu.
Vizio
Open the SmartCast app, go to Settings > Inputs > HDMI Color Subsampling and enable it for the relevant port. Newer P-Series models use Menu > Picture > Input Picture Settings > HDMI Mode > 2.1.
After making this change, your TV can accept the full-bandwidth HDMI 2.1 signal from the Xbox. Without it, even a capable TV will behave like HDMI 2.0.
Also make sure your TV firmware is up to date. Some TVs added HDMI 2.1 feature support — including VRR — via firmware updates after launch. Running an old firmware can mean missing features your TV is technically capable of.
Xbox HDMI 2.1 Settings — What to Change on the Console
Once the cable and TV are sorted, here are the Xbox settings to configure.
Go to Settings > General > TV & Display Options.
Resolution
Set to 4K UHD (3840×2160) if you have a 4K display. For a 1440p monitor, set to 1440p. For 1080p, set accordingly.
Refresh Rate
Set to 120Hz if your display supports it. If the screen goes black and doesn’t return, your TV doesn’t support 120Hz at your current resolution — it will revert automatically.
One important note: if you set the refresh rate to 60Hz, the Xbox assumes you are on an HDMI 2.0 connection and restricts the pipeline to 18Gbps. This caps colour depth to 8-bit unnecessarily even if you have HDMI 2.1. Always set 120Hz on a capable display to keep the console in HDMI 2.1 mode.
Video Modes
From TV & Display Options, select Advanced > Video Modes. Enable the following:
- Allow 4K — on if you have a 4K display
- Allow HDR10 — on for HDR gaming
- Allow Dolby Vision for Gaming — on if your TV supports it
- Allow 120Hz — on alongside the refresh rate setting
- Allow Variable Refresh Rate — set to Gaming Only for most users
- Allow Auto Low Latency Mode — on, so your TV switches to Game Mode automatically
Colour Depth
Go to Video Fidelity & Overscan > Colour Depth and select 30 Bits per Pixel (10-bit). If your screen goes black and reverts, fall back to 8-bit. 10-bit gives better gradients and less colour banding. The Xbox Series X supports 4K at 120Hz at 10-bit with full 4:4:4 chroma — you do not need to trade colour quality for the higher frame rate.
How to Check Your Xbox HDMI 2.1 Settings Are Working
Go to Settings > General > TV & Display Options > 4K TV Details. This screen lists your display’s reported capabilities and shows green ticks for features the console can confirm are active — including 4K UHD at 120Hz, HDR10, Dolby Vision, and VRR.
If a feature you expect to see is missing or shows a warning:
- Check the HDMI cable — swap it for the one that came in the box
- Check that your TV’s Enhanced Mode or equivalent is enabled on the correct port
- Confirm you are plugged into an HDMI 2.1 port on your TV, not an HDMI 2.0 port
- Update your TV’s firmware
Connecting Xbox Through a Soundbar or Receiver
If your Xbox is connected through an AV receiver or soundbar before reaching your TV, the intermediate device must support HDMI 2.1 passthrough to preserve the full signal. Most budget and mid-range receivers do not support this. They will strip 4K at 120Hz and VRR from the signal.
The clean solution is to connect the Xbox directly to the TV’s HDMI 2.1 port, then route audio back to your soundbar or receiver using HDMI eARC from the TV’s ARC port. This keeps the video signal intact and still gets audio to your sound system.
HDMI 2.1 on Xbox Series X vs Xbox Series S
Both consoles have HDMI 2.1. The difference is in target resolution. The Series X targets 4K, so HDMI 2.1 is essential for its full capability. The Series S targets 1440p, and at that resolution HDMI 2.0 has enough bandwidth for 120Hz. The HDMI 2.1 port on Series S is still useful for VRR and future-proofing, but you won’t be bottlenecked by HDMI 2.0 at 1440p the way you would at 4K.
For a full breakdown of the differences between the two consoles, see our Xbox Series X vs Series S comparison and our Xbox Series S review.
Related Xbox Display and Settings Guides
Getting HDMI 2.1 working correctly is the foundation. Once that is sorted, there are a few related guides worth reading next. Our Xbox Series X display settings guide covers every option in the TV & Display menu in full detail, including HDR calibration, Auto HDR, and colour space. If 120fps specifically is what you’re after, the how to enable 120fps on Xbox Series X guide covers in-game Performance Mode settings and FPS Boost for older titles.
If you’re setting up your console from scratch, the Xbox Series X setup guide is the right starting point. And for a broader look at the hardware itself, the Xbox Series X review covers the console’s full specs and capabilities.
For games to actually play at 4K and 120fps, the best Xbox Series X games list and the best games on Xbox Game Pass are both good reads. Check the current Game Pass pricing if you are not yet subscribed.
