HDMI Input vs. HDMI Output: What’s the Difference?

From phones to TVs, from desktop computer monitors to 4K audio equipment, there’s been some confusion lately surrounding the difference between HDMI input vs HDMI output. Plenty of modern tech products have ports for both HDMI input and output, but how exactly does this work? What are you supposed to plug into each port, and where is the other end of the cord supposed to go from there? Most importantly, what’s the real difference between HDMI input vs HDMI output? Let’s break everything down below to help make things a little more clear.

HDMI: Main Specs

HDMI Input vs. HDMI Output: Key Differences

In order to understand the key differences between HDMI input vs HDMI output, it helps to first understand two things: purpose and usage. In other words, what’s the purpose of an HDMI input vs HDMI output? And how often is HDMI input used over HDMI output? Let’s get some answers.

Purpose

The different purposes of an HDMI input vs HDMI output will tell you most of what you need to know about these two HDMI types. An HDMI input works like this: One end of an HDMI cord is plugged into the port labeled something along the lines of “HDMI IN.” The other end of the cord is plugged into an audio/video source, such as an A/V receiver or a 4K Blu-ray player. The HDMI cord then transmits audio/video data from the source into the device with the HDMI input. To understand the purpose, it helps to focus on those first couple letters of “input”: in. Audio and video data are being sent in.

Following this train of thought, we can safely assume that HDMI outputs are sending audio and video data out. One end of an HDMI cord is plugged into a port, similarly labeled something like “HDMI OUT.” The other end will be plugged into a television, a monitor, or another display device labeled HDMI IN. (Remember the illustration we outlined above.) The HDMI output will then send that all-important audio/video data out, where it will through the HDMI cord and then into the HDMI input port. It’s that simple. The purpose of the HDMI output is to send out information.

Usage

Now that we have a better understanding of the purpose of each HDMI type, what about the primary uses for each? In other words, what devices use HDMI inputs, and what devices use HDMI outputs? Let’s go over some of these primary uses for both, starting with HMDI inputs. First and foremost, a laptop computer will never have an HDMI input port. Every HDMI port found on a laptop is conversely going to be an HDMI output. Devices with more HDMI inputs than outputs include televisions, monitors, surround sound receivers, and so on.

On the other hand, there are HDMI outputs. These are just as common, but for the inverse of HDMI input devices. (Remember: HDMI outputs are the ones that send audio and video data out to display devices.) Common HDMI output devices include gaming consoles, laptop computers, 4K Blu-ray players, and so on. Anything that is designed to show or play something is going to have an HDMI output. After all, these output devices are designed to — you guessed it! — put out audio/video data. Few devices, such as televisions, will use both an HDMI input and an HDMI output.

The History of HDMI

HDMI was first released in December of 2002 with HDMI-enabled products first hitting the consumer market in 2003. Unlike the typically competitive and relentlessly cut-throat nature of the tech industry on the whole, HDMI is one of few innovations formed in partnership with multiple tech giants. More than half a dozen, in fact. Researchers and developers from Panasonic, Hitachi, Sony, Philips, Silicon Image, Toshiba, and Thomson all worked in unison to bring HDMI technology to fruition.

The collaboration didn’t stop there, either. The development of HDMI also had the backing of HDMI major motion picture studios such as Universal, Fox, Disney, and Warner Bros. alongside television providers Dish Network, CableLabs, and DirecTV. The innovative new high-definition multimedia interface was ready to go as early as late 2002, but it wasn’t until 2004 that HDMI inputs began appearing on HD televisions. (Strange to think about, considering this is the one place most are likely to encounter HDMI ports nearly 20 years later.)

By the end of 2004, an estimated 5 million HDMI-enabled devices had been sold. As 2005 came to a close, that number boomed to nearly 17.5 million. By the end of the decade, a billion HDMI devices had either been sold or were expected to be sold by year’s end. Today, an estimated 10 billion HDMI-enabled devices had been sold around the world. In short, there’s no doubt about the success and the necessity of HDMI technology in today’s digital world. Furthermore, it’s unsurprising that the technology continues to be innovated.

How the Technology Has Improved

The HDMI Forum was created in October 2011. Established due to the sheer amount of success credited to the HDMI standard, the HDMI Forum was tasked with handling any and all further development of the HDMI specification. Given all the changes going on in the field of consumer electronics at the time — from the attempted innovation of 3D technology to the burgeoning field of 4K resolution and beyond — this establishment was more than necessary. (Not to mention long overdue.)

Any company can join the HDMI Forum if they so please. According to the bylaws of the group, there’s no cap on the total number of tech companies allowed to join the HDMI Forum. The only stipulation? Any company that hopes to remain a member of the Forum must pay $15,000 annually. Additionally, any company serving on the HDMI Forum’s Board of Directors needs to contribute an extra $5,000 a year. These costs and fees help cover the further advancement of HDMI and its standards. Today, more than 80 companies belong to the HDMI Forum.

The first order of business of this newly established HDMI Forum was to implement the biggest change to the HDMI standard to date: HDMI 2.0, also known as HDMI UHD. Released in September of 2013, this new HDMI 2.0 allowed for high frame rate 3D and 4K video to be carried at 60 Hz and a color depth of 24 bit/px. HDMI 2.0a and 2.0b, released in 2015 and 2016, brought support for HDR and HDR10. 2017 saw the release of HDMI 2.1, which supports resolutions and frame rates as high as 10K as well as Dolby Atmos picture quality.

Pros and Cons of HDMI

HDMI Input vs. HDMI Output: 5 Must-Know Facts

• HDMI delivers uncompressed video data. This means that no loss of quality occurs between output and input. However, devices can compress or uncompress audio data depending on the device’s specifications.
• When HDMI cords were standardized in 2002, they replaced nearly a dozen different cords held over from the 20th century. They are sort of like an all-in-one, delivering audio, video, and metadata through one single cord.
• There are three basic types of HDMI cords with several subcategorizations underneath each tier. These include standard, high-speed, and ultra-high-speed HDMI cords. Each cord will deliver different audio/video data, ranging from 1080p HD video all the way to 10K UHD HDR HFR 3D video.
• HDMI cords are typically numbered according to HDMI standards. These numbers range from HDMI 1.0 all the way to the most recent, HDMI 2.1a.
• Most 4K televisions rely on HDMI 2.0 technology. Some more recent models support HDMI 2.1. Very few (if any) use HDMI 2.1a, as this HDMI technology is reserved mainly for video editing and mastering.

HDMI Input vs. HDMI Output: Which HDMI Do You Need?

By now, you have hopefully mastered the differences between HDMI input vs HDMI output. You know that HDMI input is for receiving audio and video data. Likewise, you know that HDMI output is for sending audio and video data. Furthermore, you understand that some devices cannot support HDMI input. Additionally, you know that TVs typically support both HDMI input and HDMI output. Thankfully, if you get confused during a setup, you can rely on the labels on the device itself. When in doubt, HDMI IN and HDMI OUT will help guide you.