Active HDMI cables are a good way to enjoy the full bandwidth of new, high-performance standards like HDMI 2.1, without being stuck to very short cables. Passive HDMI cables have limited maximum lengths, while active HDMI cables can go far longer – many times longer than passive alternatives if you use an active optical cable – without losing signal strength or image clarity.
The functional HDMI max length is directly dependent on whether you're using an active or passive HDMI cable. Here's everything you need to know about active HDMI cables, and if you're on a cutting edge setup, how to get the best HDMI 2.1 cable for your needs.
What is an active HDMI cable?
Traditional passive HDMI cables are merely the HDMI port standard connected to shielded copper wiring. That simplicity makes them great because they can transmit audio and video in either direction – that's where the super handy ARC technology comes in. Unfortunately, thanks to signal attenuation, there is a maximum HDMI cable length, and on newer standards like the HDMI 2.1 cable, it can be quite limited.
Active HDMI cables solve that problem by incorporating signal boosters to amplify the signal from the source and send it further down the line without it degrading. This means that an active HDMI cable can only run in one direction, though, so you need to connect the source end to the source and the destination end to your display. Getting it wrong won't break anything, but you won't get any kind of signal either.
An active HDMI cable can boost a signal by up to three times, making it possible to send older HDMI standards over 100ft in some cases.
How long can HDMI 2.1 cables be?
Passive HDMI 2.0 cables can extend to 20 or even 30 feet in some cases, but that’s not something the latest standard can manage. While active technology does help them go further, HDMI 2.1 cables are a little different due to their more than doubled high-frequency signaling.
At 48Gbps data rate, the best passive Cable Matters HDMI 2.1 cables can reach 10ft before they run into difficulties. That's fine for the average living room setup, connecting your new Xbox Series X, PS5, or RTX 3000 graphics card to your HDMI 2.1 TV, but you'll need an active cable to go further if you want to maintain the full 48Gbps bandwidth of HDMI 2.1
HDMI cable length for active HDMI 2.1 connections can increase dramatically whilst retaining full bandwidth. An active HDMI 2.1 cable can measure up to 25ft without difficulty, giving you much more cable reach to play with. That makes it possible to set up an HDMI 2.1 TV much further from the 4K or 8K source.
At the very high end of active HDMI cables, you also have the option of HDMI 2.1 active optical cables. They offer the highest protection against signal attenuation, therefore letting you run the cable even longer. The best fiber optic active HDMI cables can run over 30 feet and still maintain the full bandwidth of the HDMI 2.1 cable standard.
The best active HDMI cable for 4K 120Hz
You don't need an active HDMI cable to enjoy the full potential of HDMI 2.1 on new-generation games consoles and PCs. If you just want to experience high resolution, high refresh rate gaming on your HDMI 2.1 TV or monitor and it sits within 10 feet of your game console or PC, you're in luck. You can use a passive, high-quality HDMI 2.1 cable without any concern about running into the HDMI cable max length.
If you're close to that 10ft threshold, however, or want to run a cable at a significantly longer distance to offer multi-screen compatibility without placing the system and HDMI 2.1 TV side by side with each other, then an active HDMI cable is the way to go.
If you can keep your HDMI length under 25 feet, then you can enjoy all the benefits of HDMI 2.1 with a standard active HDMI 2.1 cable. It has all the shielding and signal boosting you need for 4K and 120Hz gameplay over a more extreme HDMI length.
If your HDMI cable length needs to be as long as physically possible with today's technology, though, then a fiber optic HDMI 2.1 cable is your only option. The best HDMI 2.1 cables built using active fiber optic technology can give you 10 meters or more to work with.
Cable Matters offers a certified HDMI 2.1 cable with fiber optic technology, available in lengths up to 34.2 feet. This cable is also Designed for Xbox, meaning it is built and tested to meet the demands of 4K 120Hz gaming on the latest Xbox Series X game console.
Cable Matters Certified Active Ultra High Speed HDMI® Cable