What HDMI Cable Do I Have? How to Tell If It's 2.1, and Whether It Matters

You've got a drawer full of HDMI cables, or one behind the TV that's been there for years. Then a new console, TV or soundbar arrives, and the box says it needs HDMI 2.1. So which one is the cable you've got?

The honest answer is that the cable usually won't tell you, at least not with a version number. But you can almost always work it out, and most of the time it takes a couple of minutes.

Cables don't have version numbers. Devices do.

"HDMI 2.1" describes what a device can do: the TV, the console, the graphics card. Cables are rated under a separate naming scheme, based on the bandwidth they've been tested to carry. HDMI's licensing rules don't allow cables to be sold by version number at all. That's why a genuine cable never needs to say "2.1" on it, and why one that shouts "HDMI 2.1" in big letters is telling you less than you'd think.

These are the names that actually mean something:

You'll often see "with Ethernet" on the end of those names too. That means the cable carries HDMI's data channel, which matters for eARC sound to a soundbar or AV receiver. Almost every modern cable has it.

Five ways to work out what you've got

1. Read the cable. Look along the jacket for printed text. Many cables print their category, such as "High Speed HDMI Cable with Ethernet". If it says Ultra High Speed, you have the 48Gbps tier. If it just says "HDMI", or nothing at all, assume the older end of the table.
2. Look for a certification label. Certified Premium High Speed and Ultra High Speed cables come with a label carrying a QR code and a hologram. It's usually on the packaging rather than the cable, so if you kept the box, check it. The QR code should resolve to that exact product in the official certification database. Our guide to verifying a genuine HDMI cable covers this in detail.
3. Think about where it came from. The cable in the box with a PS5 or Xbox Series X is built for 4K at 120Hz, so it's worth keeping. A cable that came with an older TV, set-top box or Blu-ray player is almost certainly High Speed at best. Ultra High Speed certification only launched in 2020, so anything you bought before then isn't one.
4. Ignore what tells you nothing. The connector size, the thickness, braided sleeving and gold plating say nothing about bandwidth. Neither does "8K" or "2.1" printed on a cheap listing.
5. Test it. Connect your 4K 120Hz source to your display and switch 120Hz on. If the picture stays solid through an hour of gaming, the cable is coping at that bandwidth. Signs it isn't: the screen blacks out for a second, white sparkles appear, HDR flickers, or the console quietly drops back to 60Hz. A cable isn't always the culprit, though, so rule out the other causes before you buy a new one.

Will an HDMI 2.1 cable work with an HDMI 2.0 port?

Yes, and it works the other way round too. Every HDMI cable fits every full-size HDMI port, and every version is backwards compatible.

An Ultra High Speed cable in an HDMI 2.0 port works perfectly. It just runs at whatever the port supports. An older cable in an HDMI 2.1 port also works, but only up to what that cable can carry, and that's where the trouble starts. The whole connection runs at the speed of its weakest link: the source, the cable or the display.

It's also worth checking which port you're using. Many TVs only have full HDMI 2.1 bandwidth on two of their four inputs, usually labelled "4K 120Hz" or "HDMI 2.1". A perfect cable in the wrong port still gets you 60Hz.

When you actually need to upgrade

Keep the cable you've got if:

• You watch 1080p, or stream and play 4K at 60Hz, and it's working without dropouts
• It's a certified Premium High Speed cable and nothing you own runs above 4K at 60Hz

Upgrade to an Ultra High Speed cable if:

• You're running a PS5 or Xbox Series X at 4K 120Hz, or using VRR
• You're connecting a PC graphics card to a TV or monitor above 4K 60Hz
• You're running 8K, or a longer cable that keeps dropping out (here's why length matters)

For the technical detail on what changed between the two standards, see HDMI 2.1 vs 2.0: What Actually Changed.

Where ElectricCrab stands on this

You'll notice our own product is called the 8K HDMI Cable 2.1. We use that name because it's what people search for. What matters is what's behind it: it's an Ultra High Speed cable rated to 48Gbps.

Our 1M, 2M and 3M lengths hold genuine HDMI Forum ATC certification, tested independently with a certificate and Test ID for each length. Our 0.5M, 1.5M, 5M and 7.5M lengths are built on the same production line, but haven't been independently certified yet, and we won't claim they have. If you want to see the certificate for any certified length before you order, ask us and we'll send it.