Tablet manufacturers love to boast about the size and technical specifications of their displays, but what is a good screen resolution for a tablet? Here's everything you need to know about displays before you buy a new tablet.

Information in this article applies broadly to a range of devices. Check the specifications of individual products before making a purchase.

Tablet Screen Sizes

The screen dimensions determine the overall size of a tablet. The advertised size of a tablet is a diagonal measurement of the screen, so two 10-inch tablets may have slightly different dimensions.

Some screens are as small as five inches, while other tablet-based all-in-one systems have 20-inch and larger screens.

Larger tablets are less portable and typically offer longer battery life and easier-to-read screens. Smaller tablets offer better portability and can be more difficult to use when reading, playing games, and watching movies.

Aspect Ratios

The aspect ratio of the display is another thing to consider.

Most tablets use the 16:10 aspect ratio that was common for early widescreen computer displays. This resolution makes them useful in landscape mode, especially for watching videos.

On the downside, the wide display can make the tablets top-heavy when used in portrait mode, which is often used for reading e-books.

The other aspect ratio used is the traditional 4:3, which sacrifices the wide display in landscape mode for a balanced tablet that is easier to use in portrait mode. Such displays aren't ideal for watching movies but are perfectly fine for reading.

Screen Resolutions

Screen resolution refers to the amount of detail on the screen at a given time. Higher resolutions are better for watching videos, viewing photos, and browsing the web.

Display resolution is expressed as the number of pixels on the screen measured horizontally and vertically. Specific screen resolutions are classified under different standards:

High-definition videos come in the 720p or 1080p format (based on the number of vertical pixels). Videos that are 1080p won't fully display on many tablets.

However, some can output video to an HDTV using HDMI cables and adapters. They can also scale down a 1080p source to be viewed at a lower resolution.

Although 4K, or UltraHD video, is growing in popularity, it isn't supported by most tablets. Tablets need dense displays to support such video. The higher resolution displays generally require more power, which reduces the overall running time of the tablet.

Furthermore, it's almost impossible to distinguish 1080p from 4K on a 7-inch or a 10-inch display.

Pixel Density (PPI)

Pixel density refers to the number of pixels-per-inch (PPI) on the screen. The higher the PPI, the smoother the rendering on the screen. Suppose a 7-inch tablet and a 10-inch tablet have the same resolution.

In this case, the smaller screen will have a higher pixel density, which means sharper images.

Newer tablet screens are advertised as having between 200 and 300 PPI. At typical viewing distances, this is generally considered as detailed as a printed book. Beyond this level, you won't be able to tell the difference.

Viewing Angles

Manufacturers typically don't advertise the viewing angles of tablet displays. Because you can view a tablet in portrait or landscape modes, it must have a wider viewing angle than a laptop or desktop display. However, some tablet screens offer better viewing angles than others.

There are two things to look at when testing a tablet's viewing angles: color shift and brightness.

Color shift refers to how the colors on the screen change when the tablet shifts from a straight-on viewing angle. The best tablet displays should remain bright enough without color shift at the widest range of angles.

Some tablet displays are incompatible with polarized sunglasses designed to reduce glare.

Tablet Screen Coatings and Brightness

Most tablet displays are protected by a hardened glass coating such as Gorilla Glass. Such surfaces are highly reflective, which can make the display difficult to use in certain lighting conditions.

If a tablet has a glossy display and low brightness, it can be difficult to use outdoors in bright sunlight. Brighter displays mitigate this problem. Still, bright displays tend to shorten battery life.

Because the interface is built into the display, the coating on the tablet PC will get dirty. All tablet displays should have a coating that allows the screen to be easily cleaned without the need for special cleaners or fabrics.

Take special care when cleaning an anti-glare display.

Tablet Screen Color Gamut

The color gamut refers to the number of colors that a display can produce. The larger the color gamut, the more colors it can display.

This number only matters if you use a tablet for video editing or production purposes. Not all companies list the color gamut for their displays. However, more tablets will likely advertise their color support as this feature becomes more important to consumers.