Technology Explained

Everything You Need to Know About HDMI Alt Mode and USB Type-C

Mihir Patkar 13-09-2016

Good news, folks! You will soon be able to connect your phones, tablets, and ultrabooks to an external monitor or TV using nothing more than the USB port. All you’ll need is a simple cable that connects USB-C to HDMI.


HDMI Licensing, the consortium that controls and licenses the HDMI specification, recently announced a new standard called the HDMI Alternate Mode (also known as Alt Mode). This allows any device with a USB Type-C port What Is USB Type-C? Ah, the USB plug. It is as ubiquitous now as it is notorious for never being able to be plugged in right the first time. Read More to output pictures to any HDMI display using the proper cable — no dongles or adapters needed. In other words, USB-C cables will be able to carry HDMI signals.

Why Is This a Big Deal?

“Consumers expect to easily connect devices to displays with a USB Type-C to HDMI cable and utilize the capabilities and features of native HDMI,” said Rob Tobias, president of HDMI Licensing.

As of this writing, you can already connect USB Type-C ports to HDMI TVs What Can You Shove In a USB C Port? Look closely at the ports on your laptop. If you bought one in the past year, you'll notice a tiny, rectangular port you've probably never used. That's the USB C port. Read More  but you can only do so with a special adapter or dongle to convert the signals. Not only is it a hassle, it isn’t even a universal standard.

USB Type-C HDMI Infographic

The new Alt Mode requires a cable that has a USB Type-C connector on one end and an HDMI connector Video Cable Types Explained: Differences Between VGA, DVI, and HDMI Ports All those video cables can get confusing. What is a VGA port? What is DVI? Learn the difference between video cable types. Read More on the other. Connect the USB Type-C end to the port on your phone, tablet, or laptop, then connect the HDMI end to your monitor or TV, and just like that you can stream your screen from the phone to the TV.


What Can You Do With Alt Mode?

Alt Mode only supports up to HDMI 1.4b, not the new HDMI 2.0 standard. This means you can get a few of the features of HDMI but will need to sacrifice some of the others. Here’s a quick summary of what you’ll get:

  • Resolutions up to 4K Ultra HD (3840 x 2160).
  • Audio Return Channel (ARC).
  • Support for 3D videos.
  • HDMI Ethernet Channel.
  • Consumer Electronic Control (CEC).
  • Dolby 5.1 surround sound audio.

Apart from streaming simple audio and video, current USB-C-to-HDMI adapters don’t support the other features mentioned above. That’s why the new Alt Mode standard is so nifty — it guarantees that everything will work just as you expect it to.

Meanwhile, the lack of support for HDMI 2.0 will mean that some of the newer features won’t be available. For example, HDMI 2.0 raises the frame rate of 4K videos from 30 FPS to 60 FPS. It also supports High Dynamic Range (HDR) video technology, which is one of the more useful TV features to come out in recent years.

Can You Use Existing Cables, Phones, and TVs?

The only existing technology you definitely can use for this new specification is the TV. Your current flat-screen TV is probably compliant with HDMI 1.x, which is guaranteed to work with the new specification.


But not all phones will work with this new technology. Some mobile devices come with a built-in HDMI chip to allow the outputting of their displays to TVs, but not all phones or tablets have it — and the ones with HDMI usually have a mini-HDMI port that looks like this:

Mini-HDMI Port on a Tablet

On the other hand, if your device has an HDMI output as well as a USB Type-C port, then you’re in luck. All you’ll have to wait for is the release of the brand new USB-C-to-HDMI cable. (No release date yet since the cables still need to be tested for compliance, but it shouldn’t be too long given USB Type-C’s rapid rate of adoption.)

It shouldn’t be too long before newer phones, tablets, and laptops are designed and released with this new standard in mind. HDMI Licensing says, “There is currently demand for this technology so new products incorporating this may be introduced at CES 2017 and launching early next year.”


Why You Should Buy USB Type-C Devices

For smartphones and tablets, USB Type-C is becoming the new standard. The port is also finding a home on laptops like the new MacBook’s single port Should the New MacBook's Single Port Scare You Away? Apple recently revealed the new MacBook, and it's a jaw-dropper — but it also has only a single port. Was this a blunder, or a sign of the future? Read More and the Asus Vivobook E403SA.

Ideally, you should wait until at least 2017 before getting a device that supports Alt Mode, but waiting that long may not be feasible for you (e.g. holiday shopping season, you’re impatient, etc). In that case, if you’re buying a new Android smartphone or Windows laptop soon, definitely get one with a USB Type-C port.

Having a USB Type-C port won’t guaranteed that it’ll work with Alt Mode, but if the device has both HDMI output and a USB Type-C port, then there’s a good chance it will work. Unfortunately, the number of devices that fit these criteria is low — not even the new Samsung Galaxy S7 Edge Galaxy S7 Edge Review and Giveaway Samsung's back again with some new smartphones: the Galaxy S7 and Galaxy S7 Edge. It's still a premium device with uniquely curved edges, but should you consider upgrading? Read More or the OnePlus 3 OnePlus 3 Review OnePlus One and OnePlus 2 were tricky to get hold of, despite attracting favorable reviews. This time around, things are different. Read More .

USB Type-C Thunderbolt 3.0 Cable


But you should start using USB Type-C regardless because it comes with many benefits, such as the reversible head. USB Type-C is also compatible with the Thunderbolt 3.0 standard Thunderbolt 3: What It Is & Why You Need to Start Using It Thunderbolt 3 may just be the only device cable you need to know about anymore. It's so awesome that it's making everything else obsolete. Here's what you need to know. Read More , which means that accessories made for Thunderbolt can be used with USB Type-C ports. For example, external graphics cards over Thunderbolt can improve gaming performance on laptops.

The Bottom Line for HDMI Alt Mode

So what does all this mean for casual, regular users like you and me?

  1. The new USB-C-to-HDMI cable will let you stream both audio and video from devices like your phone, tablet, and laptop directly to your TV.
  2. Current TVs, at least those released after 2011, should be compatible with Alt Mode. Current phones and tablets with USB-Type-C will most likely need an HDMI chip inside them to be compatible.
  3. Phones, tablets, and laptops supporting Alt Mode are expected to be showcased at the Consumer Electronics Show in January 2017.
  4. If you can wait to buy electronics, then wait for this new standard to be released before buying any new devices.
  5. If you can’t wait, make sure any new devices you buy have at least one USB Type-C port and try to check that they have HDMI chips too.

To know more about the latest standards in device connectivity, read our introduction to the different types of computer cables available in the market. And if you’re curious about whether gold HDMI cables produce better picture quality Do Gold HDMI Cables Produce Better Picture Quality? Tempted to pay extra for gold-plated HDMI cables? Learn more about whether gold HDMI cables really have better picture quality. Read More , we’ve got you covered there too.

Explore more about: HDMI, Media Streaming, Technology, Television, USB.

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  1. USBdistraught
    June 12, 2018 at 12:34 am

    I have a Samsung Galaxy 7 and want to pass through AC3 audio from the Internet to a home theatre. Since it has MicroUSB, I bought a MicroUSB to USB-C adapter, and then a USB-C to HDMI adapter (not sure if it is ALT-HDMI or not). In any case, nothing comes out from the USB the problem with system software needing an APP to route to the MicroUSB (I tried the Developer mode Audio settings to no avail), or with the Micro-USB to USB-C adapter, or do I need an OTG USB adapter, or a different cable, or what? The plethora of configurations, cables, pass-throughs etc is NUTs....please help.

  2. Nick D
    November 7, 2016 at 4:21 pm

    Something else to note - when the cable is wired for alt mode - it is not always reversible (depending on wiring at the other end).

  3. Nick D
    November 7, 2016 at 4:20 pm

    One thing to be aware of is to use Alt Mode you need a special USB Type-c cable, wired differently. Regular cables into some dongles will just not carry the video signal.

    I haven't found ANY suppliers of these cables (the only cable I have been able to test comes with the type-c microsoft dock).

  4. Ahmed
    November 3, 2016 at 12:31 pm

    "Having a USB Type-C port won’t guaranteed that it’ll work with Alt Mode, but if the device has both HDMI output and a USB Type-C port, then there’s a good chance it will work. Unfortunately, the number of devices that fit these criteria is low — not even the new Samsung Galaxy S7 Edge or the OnePlus 3."

    Why would anyone want to use USB-C to HDMI cable in Alt mode to connect to a display.

    This will sacrifice a holy precious USB-C port, and leaving the HDMI output with no use.

    The only scenario one would think of to use the USB-C to HDMI in Alt Mode is when the one only has this cable in hand and not an HDMI cable that fits their device's HDMI output.

    I don't mean that HDMI Alt mode isn't useful, but with our existing hardware today, it doesn't make a perfect sense to use it over the wide availability of HDMI .

    Unless we reach the day where the USB-C to HDMI cables are more spread than HDMI cables, this case wouldn't be

    Anyways thanks for the clarification of the Alt mode. And since I am connecting to HDMI display, it wouldn't make any difference if I buy a device with HDMI output because as I mentioned, I would connect to display using an HDMI cable whenever possible.

  5. Maurice Castonguay
    September 15, 2016 at 10:27 pm

    I think you may be wrong regarding the OnePlus 3. I got mine a just an hour ago and it came with a type C port for charging.

  6. Bill
    September 14, 2016 at 4:58 pm

    If a device like a phone or laptop has a Type-C port, how is the consumer to know which types of video connections are supported: HDMI, Thunderbolt, MHL, or none of the above? The article states that "This allows any device with a USB Type-C port to output pictures to any HDMI display using the proper cable — no dongles or adapters needed. In other words, USB-C cables will be able to carry HDMI signals." Does the cable with Type-C plug on one end and HDMI plug on the other end work in "any device with a USB Type-C port"?
    I can't wait to see the cables and try this at home!