Using a 4k TV set as a computer monitor

TL;DR Answer: Yes, a 4K TV set works as a computer monitor

with some caveats, of course.

Who is this focused on?

This article is targeted to home and office professional computer users, doing things like word processing, programming, spreadsheets, database, and other business related uses. I'm assuming your monitor is on your desk, no more than three feet (one meter for my metric readers) from your eyes.

It is NOT targeted at gamers or people wanting to share a large screen monitor with their computer from across the room (these people will probably not want to run the monitor at 4k resolution). I'm also not targeting those that might want a big screen monitor due to vision issues (hey, it will work, but I'm not an expert on this problem. And you might be very happy with a 2k big screen TV, too).

It is also not about ultra-high resolution monitors of modest size. While a printed page has commonly had 300 dot per inch resolution now for well over 30 years, the monitor has historically been limited to the 70-90 dot per inch resolution. There are new monitors on some laptops that have blown through the 100DPI resolution and are approaching the resolution found on good laser-printed pages. This is a highly noble goal, but again, it isn't what I'm talking about here.

Why?

Short version: because multiple monitors are great, but they really boil down to being a "big monitor" scattered over a few screens. Why not just have a big monitor? A single 4k monitor is 3840x2160 dots, which is exactly the same as four common 1920x1080 (2k) monitors arranged in two across and two vertically. And a 42" TV is about the same screen space as those four monitors, arranged 2x2.

So...using a "4k TV" as a computer monitor seemed to be a logical step for me.

Issues

Modern TVs are "smart" TVs

You may have noticed, it is often cheaper, or at least not much more expensive, to get a big TV screen than it is to get a much smaller computer monitor. Yes, something is going on. Smart TVs are apparently subsidized by selling information about you to advertising companies. By using it as a computer monitor, you are not broadcasting information about yourself to the makers, so don't expect them to make your life easy to use the TV as a monitor. I'm not saying it is terribly difficult to use a TV as a monitor, but be aware there are some issues.

One of the big issues is they really want to be attached to the Internet. I've yet to meet one that absolutely insisted on that, but often in the initial setup, it will moan and whine about please hook it up and "register" it. UNLESS you want to also use it as a "smart TV", don't.

Power Switch and Remote

Modern TVs are run by remote control. Most "smart TVs" live off their remote. Many don't even have a power button on the TV itself, lose that remote, you have a dark black monolith. This is annoying. IF you have a choice, try to get a TV with at least a power button...but you may not have a choice. I have four 4k TVs, two have NO buttons, one has a push button that, by holding it for various amounts of time can do various things, one has a "wobble" button that can be used to select menu functions...clumsily. The one with the wobble button runs very nicely without the remote -- push the button, it turns on. Push it again, it turns off. PERFECT. I hardly ever touch the remote. The one with the simple button turns on easily, but turning it off involves pressing and holding the one button for the right amount of time (guided by what is on the screen), so it usually gets turned on by button and off by the remote.

Unfortunately, it is hard to know what you will be getting. When I bought my first 4k monitor, I was in a time crunch, so I ran to Walmart, looked at their choices, found the ONE model they had on display that actually had a power button, bought that model ... and found it had changed, that model no longer had a power button, what was in the box didn't match what was on display.

The two I have with buttons, one it is smack in the middle of the bottom of the set, behind a distinct logo. Great. The other is off-center, with absolutely nothing indicating where the button is, at least until I put a sticker in front of the button to help me find it.

I have not seen this yet myself, but I suspect soon, we will be seeing "smart TVs" without remotes, that use your phone to control the TV. Avoid these. This will probably require that the TV be attached to the Internet. This will cause problems for a computer monitor.

Power Management

For the last 30 years, many of us have got used to not actually hitting the power button on our monitors. We turn them on, then when the computer sends a signal, they light up. When the computer stops sending a signal, they go into a very low power mode, 99% "off", but will quickly become active again when the computer sends a signal.

Apparently, "smart TVs" don't work this way. I have seen signs that some smart TVs will turn on when presented with a video signal, but none of mine do that. Most of mine will turn off after many minutes of no video signal, but the time is five to fifteen minutes, not "near instant" that I'd like. And in my TVs' cases, "off" means OFF. They will NOT fire up when the computer is attached or is powered up...it must be done by me (either button or remote).

This also leads to problems when you aren't using your computer for a while and the computer goes to "sleep" or blanks the screen, your TV may turn off...and STAY OFF when you hit the keyboard or jiggle the mouse to get its attention. So you may find yourself manually turning the monitor back on when you come back to your desk. This can be a bit of a problem if you have other monitors than JUST the big 4k monitor, as Windows will detect the monitor being off as a monitor unplugged, and will reconfigure the displays to a config without your big (and probably most used) monitor, which means all your carefully organized windows will be everywhere but where you left them. An easy fix for this is to disable the screen blanking on your computer.

I have one 4k TV that never turns off when the signal is disabled. Not a configuration option, apparently. I've walked away, and come back the next day, and it has a "No signal" message bouncing around the display 12+ hours later. I also have a friend who purchased a TV to use as a sign display at his store -- it turns out Amazon Fire TVs have an automatic power-off feature that turns the TV off after a period of time which is settable, but can't be disabled. In his case, it was a fatal problem because it would turn off (by default) after five minutes of displaying pictures from a USB stick. I have no idea what it would do with a computer signal being fed over an HDMI port, but if you are looking at an "Amazon Fire" smart TV (there are multiple brands that use the Amazon Fire features), you might want to make sure they have a good return policy if it doesn't do what you want.

Display organization

One down-side of a big, 4k monitor over multiple conventional sized monitors (and this is not a "TV vs Monitor" thing) is organizing your work. Even though you can move the mouse and applications between screens on a multiple-screen computer, the OS typically applies a little bit of logic, and will generally default to keeping an application on one screen unless you manually enlarge it beyond the one screen. I'm not the most organized person, and I very often find myself looking for an app that has got buried under five other applications. On the other hand, I know people that keep a big monitor very well organized.

What Size?

The "Seems Right To me" size for a 4k monitor-as-TV seems to be 42-43inch. I also have a 50 inch TV, but it just seems a little big to see all the screen easily. 42-43 inch is almost exactly the screen space of four 23" 1920x1080 monitors, almost exactly the same dot size. 50" just seems a little too big for me. BUT you may disagree. IF your eyes focus best a little further away than a normal monitor, you may want a 50" or even bigger set, and place it further back on your desk. My 50" TV is over a foot away from the wall behind it, so the screen is about the same distance as most of my other screens. If I slid it back, I'd probably appreciate the 50" more (but then, that's not where my vision is optimal). Your mileage WILL vary here. I'm just offering a guideline.

Will it work with my computer?

IN MY EXPERIENCE, most computers made in the last four or five years work just fine with 4k monitors or 4k TVs used as monitors. I have some much older ones that do as well -- I have tested a 2014 netbook that had an HDMI port on it, and it drove the 4k monitor just fine, though a somewhat newer and much better laptop did not. But so far, everything I've tested within "office refresh" age (3-5 years) has worked great with a 4k TV or monitor. You do need either an HDMI or Display Port output. Your TV will almost certainly have an HDMI input. HDMI to HDMI cables are dirt cheap, DisplayPort to HDMI cables are a little more expensive, but not bad at all.

Will it work with my operating system?

Probably.

Windows 10 defaults to a 300% magnification with a 4k monitor, I'm guessing this is due to wanting to make sure you can read it if your monitor turns out to be "normal" sized. Fine, but you will probably want to knock it down to 100% so that you get the benefit of four monitors screen space and dot count.

I've used it on OpenBSD, which also Just Works. If your primary/only monitor is a 4k display and your hardware supports it, it should just take off and run. If your monitor is attached at boot as a secondary monitor, it should also take off and work, but you might need to use xrandr to position the monitor as you desire.

Do I need an expensive cable?

NO.

HDMI and DisplayPort are digital signals. They either get through the wire or they don't. Yes you can get a garbage cable that won't work, but spending crazy amounts of money for gold plated stuff is cheating yourself. Not only will you not see the difference, there's no difference to be seen. Yes there are garbage cables out there. Unfortunately, I'm not sure of a good way to identify a cheap cable that is just fine vs. an expensive cable that is junk.

Get a stand

One problem with using a TV as a computer monitor is the stand that comes with the TV is generally designed to stand on top of a surface with little clearance between the surface it sits on and the bottom of the screen. I find this too low -- I like having my nose at approximately the center of the screen. On my first 4k TV-as-monitor setup, I put the TV up on some books to raise it up. I found a much better solution with something like this or this. These give you some flexibility about how high the monitor is above your desk AND give it more stability. They also give you the ability to use the space on your desk immediately under the monitor, and I highly recommend a stand to replace the plastic legs your TV will come with (I do NOT get any kind of compensation if you buy one of those. I have a couple of the pedestal stands under my 4k monitors, and I've used the two-leg stands to put "standard" size monitors in a vertical (portrait) position, and I'm quite happy with both. The two leg stand is really much better than I imagined -- it looks kinda spindly and weak, but it is actually quite solid and quite heavy).

Selecting your TV

Typically, a TV is viewed from many feet away, if not across a room. A computer monitor is viewed from a very short distance. One thing I have found that is different between monitors is viewing angle. LCDs are somewhat directional by nature, so if you are sitting towards the left side of the monitor, when you look at the right side, you may see some color and intensity differences. So when you pick your monitor, put yourself at viewing distance on one side, then turn your head and look at the other side. One of the TVs I have has a minor issue with this; $180 for a 42" 4k TV, I am not complaining, it is 100% usable, just something I notice, and I kinda wish I had looked harder at the $20 more expensive one -- if it had a better viewing angle, it would have been well spent (and if it didn't, would have been wasted).

What TVs do you have, Nick?

I have four. I'm not going to provide model numbers, because even when the model numbers are the same, I've found differences, and my most recent purchase was a close out anyway. The others are all a couple years old at this point. Anything I tell you about mine may or may not apply to the same brand and same marketing model number...and most likely, you can't find the same model at this point anyway.

Perhaps more useful is who provides the "smarts" for the Smart TVs. As I indicated above, I have seen issues with power management on some Amazon Fire TVs which rendered them unusable for some applications, but I don't know how those issues would apply when being used as a computer monitor (I suspect it wouldn't matter...but make sure you have a good return policy if you buy one).

I've got two "Roku powered" TVs, and they both work fine as computer monitors. Neither has a power button, both have visually the same remote. Both refuse to turn on automatically when presented with an HDMI video signal, but they do turn off on their own when the signal goes away. The two monitors were purchased about three years apart from each other, so that may indicate some predictability. My most recent was purchased in December 2024.

I heard TVs make horrible computer monitors!

Until the modern digital TV, yes, that was true. The technology of broadcast TV was developed in the 1940s, and it showed when you tried to attach a high resolution computer to them.

This is not true of modern digital TVs. There are some purposes for which a very high end computer monitor will do better for you than a TV used as a computer monitor, but in terms of sharpness of image, the modern TV set will be sharper than even the best CRT computer monitor ever was, and similar to a standard computer monitor.

Don't I need a faster refresh rate than a TV will provide?

For games and maybe some action videos, perhaps. But for office use, a 30Hz refresh rate is fine.

Again, if you have been in a computer user since the 1990s, you might cringe at the idea of a 30Hz refresh. But remember, LCD monitors and old CRTs are different beasts. A CRT monitor that is running at a 30Hz refresh means the beam draws out the entire picture 30 times per second. Only one spot on the screen is lit at any instant, so the screen is flickering and quite annoyingly, unless that rate is 60Hz or better. LCD screens do not flicker as part of drawing the image. When you see a computer driving an LCD and refreshing only 30 times per second, the entire image is being updated 30 times per second. It isn't flickering, it's a steady image from one refresh to the next.

So for eye strain and such, refresh rate doesn't matter. For games and action stuff, it may...but as I said at the beginning, that's not my use case here.

I did find in one of my environments, the only one that supported a 60Hz refresh on the 4k monitor, the image looked sharper at 30hz than 60hz. I'm not sure if that was my dock station, the monitor, the cable, or the computer. Experiment.

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