HDMI 2.1 is the HDMI generation that raises the cable ceiling from about 18Gbps (HDMI 2.0) to 48Gbps. That extra headroom is what makes 4K at 120Hz, Variable Refresh Rate (VRR), Auto Low Latency Mode (ALLM), and richer eARC audio practical on one cable between a console, GPU, or streamer and a TV or monitor.
This guide is about the interface and the cables. For routing one source to many displays, see What Does an HDMI Matrix Do?.
What Is HDMI 2.1, Really
HDMI 2.1 is a bandwidth and feature bump, not a new plug shape. The connector still looks like every other full-size HDMI plug. What changed is how much video and audio the link can carry, plus a set of optional features manufacturers can implement on the ports.
A useful picture: HDMI 2.0 is a two-lane highway. HDMI 2.1 is a six-lane highway. Your car (the cable) has to be rated for the faster road, and both on-ramps (source and display ports) have to support the feature you want. An Ultra High Speed HDMI cable is the cable class designed for the full 48Gbps HDMI 2.1 feature set.
Marketing loves the word "8K." Most living rooms will feel HDMI 2.1 first as smoother 4K gaming and cleaner Atmos handoff to a soundbar, not as actual 8K movies.
How It Works
Bandwidth first. HDMI 2.1 tops out at 48Gbps. That is enough for uncompressed 4K at 120Hz (and higher refresh at 4K with the right panel), or 8K at 60Hz. HDMI 2.0 tops out near 18Gbps, which is why many 4K120 modes fail or silently fall back on older cables.
4K120. PlayStation 5, Xbox Series X, and modern GPUs can output 4K at 120 frames per second when the TV or monitor's HDMI port and the cable both allow it. That is the single most common reason to upgrade.
VRR and ALLM. Variable Refresh Rate lets the console or GPU match the display's refresh to the rendered frame rate, which cuts tearing and stutter. ALLM tells a TV to jump into game mode automatically. Both need HDMI 2.1-class support on the display side (and a cable that does not choke the link).
eARC. Enhanced Audio Return Channel carries higher-bitrate object audio (Dolby Atmos, DTS:X) from the TV back to a soundbar or AVR over the same HDMI cable. Many ARC-only links were fine for basic surround and still are. eARC matters when you want the full Atmos bitstream instead of a compressed fallback.
Feature optionality. A port labeled HDMI 2.1 on a TV brochure does not guarantee every feature on every input. Check the specific input for 4K120, VRR, and eARC. Consoles often need a labeled "HDMI 2.1" or "4K 120Hz" port.
Who Actually Needs One (and who can stay on 2.0)
You need HDMI 2.1 when any of these are true:
- You game on a PS5, Xbox Series X, or PC at 4K120 (or 1440p120+ over HDMI).
- You want VRR / ALLM on a TV that supports them.
- You are sending Atmos / DTS:X from the TV to a soundbar or AVR over eARC.
- You are connecting a high-refresh 4K monitor that only hits its rated mode over HDMI 2.1.
You can stay on HDMI 2.0 when:
- You mostly stream Netflix / Disney+ / YouTube at 4K60 HDR.
- You watch 4K Blu-rays at 24 or 60Hz.
- Your TV's "game" HDMI port is still 4K60 only.
- You only need basic ARC to a soundbar, not eARC object audio.
Bold takeaway: most households do not need to rip out every HDMI 2.0 cable tomorrow. Upgrade the one run that sits between the console (or GPU) and the 120Hz display first.
What to Look For
Shop the cable with a short checklist:
- Ultra High Speed HDMI certification with the official logo / QR label when possible
- 48Gbps called out explicitly (not just "high speed" or "4K")
- Length you actually need (shorter is more reliable at full bandwidth)
- eARC / VRR / 4K120 language on the listing if those are your goals
- In-wall CL2/CL3 rating only if the cable will live inside a wall
- Known cable brands with real review volume (Cable Matters, Amazon Basics, Monoprice, Belkin)
Skip listings that only shout "8K" with no certification story and no 48Gbps figure.
The Best HDMI 2.1 Cables You Can Buy Right Now
These are currently sold Amazon US Ultra High Speed / HDMI 2.1 cables with real ASINs. Prices move; treat the figures as a snapshot.
Best overall: Cable Matters 6.6 ft certified
✓ Pros
- ✓ Official Ultra High Speed HDMI certification language
- ✓ 48Gbps with 8K60 / 4K240 claims for consoles and GPUs
- ✓ Sensible 6.6 ft living-room length
- ✓ eARC and HDR feature support called out clearly
✕ Cons
- ✕ Longer lengths get thick and stiff
- ✕ Smaller review sample than Amazon Basics
- ✕ Occasional buyer reports of missing QR packaging on some variants
The Cable Matters 6.6 ft Ultra High Speed cable is the default pick for a PS5 or Xbox Series X to a 4K120 TV. Reviewers consistently report clean 4K120 HDR gaming when the TV port cooperates. The recurring complaint is stiffness on longer SKUs, which matters more if you are yanking a lightweight HDMI switch around.
Best budget short run: Amazon Basics 3 ft
The Amazon Basics 3 ft HDMI 2.1 cable is the high-volume, low-drama short cable for a console that sits next to the TV, or a PC under a monitor arm. It is Certified Ultra High Speed, about $7, and sits on thousands of reviews. The catch is length: 3 ft is useless across a room, and a few buyers wish the jacket called out "2.1" more obviously for cable swaps later.
Best slim cable for tight spaces: Cable Matters thin 4.9 ft
Wall-mounted TVs and crowded AV racks hate fat HDMI plugs. The Cable Matters thin 4.9 ft HDMI 2.1 cable keeps the 48Gbps Ultra High Speed rating in a 3.2mm jacket with a low-profile connector. Best for travel docks, Switch-to-hotel TV, and shallow wall mounts. One real-buyer caveat: a few people report monitor audio quirks, so confirm speakers after you plug in.
Best in-wall rated: Monoprice 6 ft CL2
If the cable will live inside a wall, fire rating matters. The Monoprice 6 ft Certified Ultra High Speed cable adds a CL2 in-wall rating on top of 48Gbps, eARC, VRR, and Dynamic HDR support. Gamers often buy it to replace flaky console pack-in cables. Watch length: some longer Monoprice runs get mixed 4K120 reports, so keep in-wall pulls as short as the room allows.
Best premium brand pick: Belkin 6.6 ft
The Belkin Ultra HD HDMI 2.1 cable (6.6 ft) is the name-brand option with double-layer shielding and strong 4K120 reports on OLED TVs and high-refresh monitors. You pay a clear premium over Cable Matters or Amazon Basics for similar rated bandwidth. Buy it when you want Belkin support and build, not because cheaper certified cables cannot do 4K120.
| Cable | Length | Cert / bandwidth | Standout | Price snapshot | Best for |
|---|---|---|---|---|---|
| Cable Matters Ultra High Speed | 6.6 ft | Ultra High Speed / 48Gbps | Console-ready default | about $12 | Most living rooms |
| Amazon Basics HDMI 2.1 | 3 ft | Ultra High Speed / 48Gbps | Huge review volume | about $7 | Short desk / TV stand |
| Cable Matters Thin | 4.9 ft | Ultra High Speed / 48Gbps | Ultra-slim jacket | about $15 | Wall mounts, tight racks |
| Monoprice Certified | 6 ft | Ultra High Speed / 48Gbps + CL2 | In-wall fire rating | about $12 | Behind-wall pulls |
| Belkin Ultra HD | 6.6 ft | HDMI 2.1 / 48Gbps | Premium brand build | about $35 | Brand-first buyers |
Bottom Line
If you are chasing 4K120, VRR, or full eARC Atmos, step up to an Ultra High Speed HDMI 2.1 cable on that one critical run. Start with the Cable Matters 6.6 ft for a normal living room, the Amazon Basics 3 ft when the console sits beside the TV, the Cable Matters thin 4.9 ft for tight mounts, or the Monoprice CL2 when the cable goes in the wall. Reach for the Belkin 6.6 ft only if you specifically want that brand tax.
Everyone else can keep a known-good HDMI 2.0 cable on streaming boxes and Blu-ray players. The interface upgrade is real. It is just not mandatory for every jack on the back of the TV.
