I have searched dozens of forums for this solution on multiple occasions, and the answers are always instructions on monitor rotation or simply, Why do you need to do that anyway?

Yes, I can rotate my monitor, but that doesn't address my need. I work with amputees and have a virtual model of a right arm that they control in real time using advanced surface electrode control strategies. I've been stuck using this right hand virtual arm with individuals who lost their left arms, and that can be distracting. Until an identical model exists for both arms, I'd like to simply flip or invert the screen horizontally to produce a mirror image. This would give me a left arm model that would function just like the right. I make the arm a full screen image, so there is no concern about backwards text, etc. It would be nice to toggle back and forth with this monitor flipping, but that's not critical.

I run the signal processing, decoding, and visualization on an ASUS G75 with the NVidia GeForce GTX 660M. The computer can handle quite a bit, so even if the proposed solution was CPU intensive, I don't think that would keep me from running the real-time simulations I use.

There are no built-in inverting features in the NVidia control panel that I can find. There are plenty of flipping options, but there are no mirroring or inverting options. Any suggestions are much appreciated.

Updates: I am using Windows 7. The Ctrl+Alt+Arrows are shortcut keys to rotate the display. Suggested answers to the identical question from a couple years ago are all either 1) rotation tips, 2) Why do this anyway? or 3) use your video card's built-in features. I addressed all of these in previous paragraphs. Perhaps it is not possible with my NVidia GeForce GTX 660M and Windows 7.

  • It might not be possible.
    – BenjiWiebe
    Feb 20, 2013 at 3:40
  • 1
    What I can imagine is to use two monitors. Then you use a screen capture program to "film" the other. And then somehow you replay that video in real time on the other monitor, with a mirror "filter" enabled. OR you could just look into finding someone to design you a set of actual mirrors. Surely that's doable.
    – Ariane
    Dec 1, 2013 at 16:54
  • 1
    With old CRT monitors you'd get someone to swap the leads on the yoke. Dunno of a way to do that here. But it seems to me that the problem is with your simulator software -- it ought to be capable of flipping to the opposite orientation -- a very simple thing at that level. Have you contacted the outfit that created that software? Jan 4, 2014 at 13:50
  • > "I run the signal processing, decoding, and visualization" If you have access to the source code for this it should be possible with some small programming component.
    – RJFalconer
    Sep 9, 2014 at 10:48
  • 1
    Honestly a physical mirror may be easiest. Arcade machines used them.
    – LawrenceC
    Sep 9, 2014 at 12:15

10 Answers 10


I had the same need for a content displayed within a browser, where I ended up using CSS tip to flip the element :

    transform: scaleX(-1);

Not sure it applies to OP situation, but could help others.

  • OP is asking about his display. He never mentioned HTML.
    – Makonede
    Mar 18 at 22:56
  • @markonede : hence 'Not sure it applies to OP situation, but could help others.'
    – Uriel
    Apr 18 at 17:35

I know exactly what you are trying to achieve. I'm running a three display setup in Windows extended desktop mode where one of the displays is in a teleprompter and needs to be horizontally flipped (left right flip) so that the mirrored reflection is the correct orientation.

Of the software options I investigated only Ultramon can do this. However, it can't do it in the extended windows display mode, it switches to duplicating the same monitor.

There are two hardware products that can do this: HDMI Mirror Box and the Decimator MD-HX. I've owned both.

  • The HDMI Mirror box defaults back to the original settings each time it is powered off and it is confusing for end users to reset properly. Further, mine stopped working after 18 months (the warranty period is one year).

  • I've just purchased the Decimator MD-HX and the Horizontal Flip parameter in the Scaling settings will do what you want. Further, the MD-HX is a vastly superior build quality to the HDMI Mirror box in my opinion and it autosaves the settings so that when it is powered off and restarted it maintains the settings you want. It also has a very useful USB connection and software interface where you can update the firmware and access all the settings menus.

For the sake of transparency, I have no association or commercial interest in any of these products.


Try UltraMon. It lets you flip both vertically and horizantally (independently). It also provides a number of other useful features for using multiple monitors.

  • This "mirrors" the monitor? Or rotates it?
    – BenjiWiebe
    Jun 17, 2014 at 14:14
  • I don't know why Rick didn't respond — although it looks like answering this question was the one and only thing he ever did on Stack Exchange.  realtimesoft.com/ultramon/tour/mirroring.asp suggests that UltraMon can mirror one or more (entire) monitors, only a single application, part of the desktop, or the area around the mouse pointer. Apr 14, 2015 at 21:20
  • UltraMon has left-right mirroring capability, but it requires a separate source monitor that is natively rendered by the GPU. It does not allow flipping pixels "in place" without an additional physical screen. I suppose one could create a "dummy" screen device that ghost-rendered pixels, but you'd still need an additional video source connected to your machine, or something like a HDMI-to-USB3 or DisplayPort-to-USB3 converter like this: amazon.com/StarTech-com-External-Monitor-Graphics-Adapter/dp/…
    – lightw8
    Mar 30, 2021 at 18:48

There is a Chrome extension called Flip This: Check out "Flip this".


"Ultramon" can do this. You have an evaluation version for 30 days. You may need at least 2 monitors.

Ultramon can really flip the monitor like if you are looking at it in a mirror if you want to read something on your monitor you need a mirror because it is reverse.

  1. right click on the icon in the task bar,
  2. click mirror in ----->>> setting ----->>> one or two monitor
  3. select the monitor on witch you want so see flipped.
  4. click flip horizontally (or vertically) then you have a flipped screen.

End result:

enter image description here

  • why -1 ? ultramon can really flip the monitor like if you are looking at it in a morror if you want to read something on your monitor you need a mirror because it is reverse. how to do it?? Sep 9, 2014 at 10:19

Two thoughts. First, you can buy hardware that does this to a video image "en route" to the monitor. They use this for driving teleprompt/autocue systems.

Sedcond, I know you said you were using Windows, but this is trivial, out of the box, behavior on Linux:

xrandr --output --reflect-x

I use this for driving my teleprompter :) much cheaper!


I have solved this and it a free solution for now.

You will need Google Chrome, an extension called Flip this and spacedesk.

Install Space desk on your computer. Let it run Install Flip this on Chrome. Go to a fresh tab and go to http://viewer.spacedesk.net/ Go to download then press "5 Html Viewer 5 page" button Please enter your primary-PC network address Boom, you have a second monitor. Configure how you want your second screen to behave in Windows display settings. Configure how you want to flip your second screen in flip this extension.



PrompterPeople sells a monitor with a reverse function but it is $375.
Amazon has small high resolution monitors (like 6" or 7") that have a Flip function. Eg Neewer FW568.


I found another solution, that uses a dummy display dongle and OBS. In the end you need 3 displays (1 main display, 1 teleprompter display, 1 dummy or virtual display)

With this setup you can start OBS in studio mode, create a scene with screen capture, capturing the dummy display. On the left side of OBS you right click on the captured screen --> transform --> flip Horizontal. Click on Transition. On the right screen in OBS you right click --> Fullscreen Projector --> select your teleprompter display. It works way better than ultramon. 60fps with just a low CPU load.


@Neptoos, great idea and I think it will work, but my problem is my main monitor turns black when I turn on the Projector. Is there a way to turn that off so I can still use my main monitor?

I found the issue and fix for MAC,

"I had this same issue when 25.0.7 came out. (25.0.8 doesn't fix the issue, as reported above) What appears to happen is OBS opens a new "Space" (virtual desktop) that's black, and switches into it. The Fullscreen Projector Preview is the only display that behaves correctly. It appears that if you go into System Preferences and open up the Mission Control settings, then check the "Displays have separate Spaces" option (you'll have to log out for it to take effect), this seems to make things work. (I unchecked the other boxes but I don't know if this is necessary) I haven't tested this really at all, since losing my job, I no longer have a need for OBS... but I do have time to find workarounds like this. :-) Curious to hear if this helps anyone though."


  • Welcome to SU. Please take the Tour to learn what SE sites are in general. These aren't discussion forums, but Q&A sites. Next please go through the pieces of advice in [the Help] to get an understanding how to answer and ask; among other things. Also it's advisable to just look around to see how other members are answering. I'm sure you can in the future offer valuable input :-) Oct 1, 2021 at 19:17
  • If you have a new question, please ask it by clicking the Ask Question button. Include a link to this question if it helps provide context. - From Review Oct 1, 2021 at 19:18

Not the answer you're looking for? Browse other questions tagged or ask your own question.