How-To Geek

How to Tweak ClearType in Windows for Better Screen Readability

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ClearType is font-smoothing technology built into Windows to help make text more readable on LCD monitors. If your text is looking a little blurry, tweaking your ClearType settings can definitely help.

There are a few issues that can cause slight blurriness. For starters, you should always use your monitor’s native resolution. Windows uses the native resolution by default, but some games and other apps can lower it and then not reset it properly when they’re done. Also, Windows doesn’t always handle high-DPI displays well without a little tweaking. If neither of those are the cause of your blurry font troubles, the chances are that tweaking your ClearType settings will help.

The instructions in this article apply to Windows 7, 8, and 10, where the ClearType tuner is built in. If you’re still using Windows XP or Vista, you’ll need to download the ClearType Tuner PowerToy for XP (which also works in Vista) and follow the the instructions in this guide. It works very similarly to the built in tuner we’re discussing here.

What Is ClearType?

ClearType is a font smoothing technology first introduced with Windows XP. It is designed to smooth the fonts on your screen with subpixel rendering so that they are more readable on LCD displays. Fonts can easily look jagged and pixelated on LCD screens since they have fixed pixels. This was not a problem with earlier CRT screens, which do not have fixed pixels.

ClearType uses multiple color shading on text to make it look more readable, whereas traditional text rendering only shows only black pixels that can often appear jagged on an LCD display. So, at 500% magnification, standard text rendering looks like this:

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When you enable ClearType, text rendering look like this. Notice the color shading around the characters, which gives the fonts a much smoother look on LCD screens.

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When you bump down the zoom to normal levels, you can see the difference in readability when ClearType is turned off (on the left) and turned on (on the right).

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How to Turn ClearType On or Off

ClearType is enabled by default in Windows 7, 8, and 10. To turn ClearType on or off, you’ll need to launch the ClearType Text Tuner. Hit Start, type “cleartype,” and then select “Adjust ClearType text.”

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To turn ClearType on or off, just select or clear the “Turn on ClearType” option and then click “Next.”

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If you’re turning ClearType off, the wizard will act like it’s going to run you through the ClearType tuning process, but then will give you the opportunity to finish and save your settings. If you’re turning ClearType on—or just want to leave ClearType on and tune it—the wizard will step you through the tuning process (which we’ll cover next).

Tune ClearType for Your Display

In the ClearType Text Tuner, when the “Turn on ClearType” option is enabled and you click “Next,” you’ll get the opportunity to tune ClearType for your display. If you have more than one monitor, you’ll get the the choice of whether to tune all your monitors in turn or just the one you select. We’re just going to tune one in this example, because all the tuner does is run you through all the same steps again for each monitor you have. If you only have one monitor, you won’t see this screen.

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The first thing the tuner will do is make sure the display is set to its native resolution. If it isn’t, you’ll need to change this first. If you’re unsure how, read through our guide to using your monitor’s native resolution.

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Next, you’ll be taken through 4 or 5 screens (depending on your version of Windows) where you’re asked to choose the text that looks best to you out of several examples. The highlighted selection is your current setting, but you can click the example that looks best on each screen and then click “Next.” Just use your best judgment and pick the one that feels right to you.

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When you’re done, click “Finish.” If you have more than one monitor and elected to tune them all, you’ll be taken through the same tuning steps for the next monitor. Otherwise, you’re done and the tuner will close.

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Tuning ClearType can definitely help you get the best looking text on your display. Even if you’re not having issues with blurriness, you might want to run through the tuning options just to see whether you optimize your onscreen reading experience.

Matthew digs up tasty bytes about Windows, Virtualization, and the cloud, and serves them up for all to enjoy!


Walter Glenn is a long time computer geek and tech writer. Though he's mostly a Windows and gadget guy, he has a fondness for anything tech. You can follow him on Facebook and Twitter.

  • Published 01/5/17

  • Jamie

    Re the comment about LCD having fixed pixels and CRT not having fixed pixels -LCD's have a fixed cell resolution (as in 1080 lines of 1920 cells)CRT's have phosphor clusters ( equivalent to cells of a CRT, but a CRT sets the colour over the whole cell, a CRT has the appropriate colour dots of the set ( as in RGB 0-256) energised to the required level to illuminate that portion of the screen to the required hue and intensity.

    So - there is, effectively, the same problem with CRT and LCD

    Now - a major problem for purchasers is that the electronics between the input socket, and the screen are frequently not as good as the screen description makes you think.

    And - whatever device - there is always going to be the best output if you set your PC (whatever) to generate images (from the video board) that match the physical screen capability.

    Basically, the 'image' to be displayed should be a whole number of the screens physical resolution, or the screen will have to guess at what to display -So if the image to be displayed is a red rectangle 16 'pixels across and down, bounded by sides shown using a 1 pixel thick blue line 0 then the 'image' is 18x18

    Send that to a screen where the pixels of the image in the PC's video system matches the screen - and you should see a block of red with a blue surroundIf you have told the PC to work as if the screen has, say 2/3, of the colour elements - and that means there will be rows/columns of the display trying to show both red and blue and - blue and the background colour - so you may get part of the surround being purple or brown, or green - just depends on how good the display's electronics are -Effectively it's like you trying to fill in 5mm squares on a bit of graph paper using a 8mm paintbrush - it's going to be smudgy

    Similarly, if the PC is set to a higher resolution than the screen can manage - the screen is going to have to split the extra cells? that come at the boundaries of colours - as in sending white, blue, red red to a row of 8 display elements means you get white, white, blue, blue, red, red, red, redand sending them to a row of 6 elements mean -white, ?, blue, red, red, red now - what if those get sent to a row of 5 - now the middle one needs to be blue and red at the same time .

    Then add to that the electronics in the display - remember HD ready - as in feed in a 1080 HD signal, and have it displayed on a 728? row screen - you do the arithmetic - and then consider sending a 4K signal to a TV that has internal electronics that work at HD rates - as in the input signal gets converted to 1920x1080, and then, the 'colour' of each of those 'pixels' gets displayed on 4 screen cells. So the blue corner of the rectangle (3 blue and 1 red ) gets you a purple block.

    BUT - whatever you do use for the display - for text- there is always a possibility that Cleartype will make what is on the screen more acceptable to your eyes, and especially so if the display, and the electronics, and the video resolution you set, and the image size you have selected are not a perfect fit

  • Biswa

    For information: The path of main executable (ClearType Tuner) is::"C:\Windows\System32\cttune.exe"

  • Tom Wilson

    The size and density of these clusters was known as "dot pitch", and it was one of the limiting factors in CRT resolution. Unlike an LCD panel, CRT pixels and the computer pixels never line up 1:1, and they are not supposed to. Also, CRT dot pitches were usually upwards of 90DPI, which at arm's length means that individual pixels are not discernible. Finally, as picture tubes got larger, the dot pitch remained constant, so a 25" CRT has the same size pixel as a 15" display. My 25" LCD panels have much bigger pixels than my laptop does, even though both run at 1920x1080. So the image on the bigger panel is more aliased than on the smaller monitor. I actually improved my image quality on my home PC by shifting down to a trio of 24" displays. That one inch difference makes enough of a difference in DPI that the picture looks like a single image, rather than a collection of squares.

    Speaking of squares: LCD pixels are rectangular, and the Human eye tends to notice sharp corners. When the same image is displayed on a CRT screen, the round pixels on the CRT tend to blur the edges just a little, reducing the aliasing effect of computer pixels. Neighboring cells can also be lit up by the electron beam, which also creates a natural anti-aliasing effect.

    So viewing computer graphics on a CRT always has a natural anti-aliasing effect, partly because the dot pitch, is always higher than the displayed image, partly because it's high enough that it's difficult for the eye to discern individual pixels, and partly because the pixels are rounded.

    Finally, CRT's are not meant to have a 1:1 relationship between the displayed image and the phosphors. This means that there is no "native resolution" on a CRT screen, and every image at every resolution smears pixels across multiple cells on the CRT.

    So yes, cells on a CRT are also fixed, but the relationship between the image and the pixels on a CRT are never 1:1, which makes for a very different image than an LCD screen.

  • Jamie

    Re CRT lining -up, with almost all 'quality' CRT's the user could adjust the frame size so that the dot-groups in use actually matched the video facilities working resolution, so achieving a 1:1 correspondence.Dot pitch was frequently different depending on the size cost and quality of the screenAs in I had a 19" screen that did 1920x1440, and was then got advised to go for the 21" @ 2560x1920 - BUT, on checking, found that, although the dot-pitch was as needed for the 2560 , the display electronics were only capable of 1920x1440, consequently, the display was actually inferior - either small image needed, or massively naff image due to the merged pixels.Re LCD panels - I would, for price point users to 27" screens, however, with the 16:9 aspect of most current screens 1920x1080 (or wider) I note that most users will exercise their neck to the point of stress when trying to look at both sides of a screen at normal desk-top distances. Above 25", users should check that they can make comfortable use of the viewing area with the viewing angle they will have.Yes - curved screens help - but the 3 screen config (angled to the viewer's eyes) is much better - and then, with that, maybe a double stack for a panoramic viewpoint/almost imbedded aspect.

    Re rectangular display cells - Yes, - but the better 'full HD' ones are not only physically a 16:9 aspect, but also have square pixels.Same with quality CRT's at a 4:3 aspect - just depended on a correct setup to match the actual dot-pitch of the phosphor sets - if you got a CRT with the right specs you could setup a 1:1 aspect of PC pixels to display phosphor sets.

    As in all things technological - cost and label ( stuck-on-sellers badge) do not often mean appropriate design to match the appropriate standards, or even a good set of components, let alone a quality build.

    Indeed, when LCD's were just 'coming-in' with the high-power, large memory video boards, I was setting up systems for CAD/CAM and high-res images ( sort that needed an A0 plotter rather than an A3 printer), and mostly I was using video boards with under 128MB memory as they did not 'manage' the image, but just displayed it as generated by the cad software - giving sharper images and text - such that single pixel wide lines usually appeared as solid rather than dotted.dash and wavering across a 2 'cell' width on the screen - also nice, at a reasonable zoom-out to be able to tell the difference between lower-case s, e, a and to be sure about o's.

    So - CRT's could be obtained with dot-pitch that matched high resolutions available on video cards LCD's can be obtained with square cells - up to the user to check the physical aspect of the screenYes - CRT's had a smudge effect - if from nothing else than the slightly off-set arrangement of those phosphor groupsBUT - for those looking for 4K TV as a display - check the actual capability of the electronics in the thing - 4K in, processes as HD and then displayed on a 4K screen, just mean blocks of 4 screen cells used for the 'merged/muddied' set of the useage specifications for those 4 input cells.And for those looking at HD and 4K - you really need to pick one or the other, or a set that gives an appropriate black border when using the smaller resolution.

    AND ... Yes - there are lots of sizes and resolutions available, BUT, it's the viewing distance and angle to the middle, and corners of the screen that matter, as in does it look good to (you) the viewer. And on your possible purchase screen, running from your preferred video board/display image generator facility, can you see the thin lines and maybe the actual cell where single pixel wide horizontal and diagonal line cross? - if NOT, why NOT?on a 4K TV - Chroma 4.2.0 perhaps?

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