How to Choose a Tempered Glass Screen Protector for My Phone?

how to choose glass for your phone

by Alex Gustman

Updated: August 13, 2021

The tempered glass screen protector is the most popular accessory for smartphones. Since the protective surface eliminates the formation of scratches on the front panel, as well as reduces the likelihood of damage in the event of an impact. At the same time, in addition to the protective properties, it is important to take into account other parameters to avoid deterioration of the sensor performance and information display. The article contains important recommendations that will help you choose the most optimal glass for your smartphone.

Type of Protective Surface

Protective glass should be understood as tempered glass obtained as a result of thermal or chemical hardening. After processing, the protective surface better tolerates shocks and the absorption of mechanical energy. Such an accessory is preferable in terms of protection in comparison with other types of screen protectors. Read more about the properties and varieties in the article What is Tempered Glass Screen Protector.

tempered glass

There is also a liquid glass in the form of a gel that is applied to the surface and smeared with a thin layer. After solidification, the resulting layer, in theory, provides reliable protection, in practice, the protective properties are worse than a conventional film. Therefore, it is not recommended to use liquid glass.

There are also conventional and hydrogel films on sale. In comparison with a conventional film, the hydrogel film tightens small scratches, which makes it last longer, and also smoothes air bubbles, in case of incorrect installation. At the same time, the protective properties of the film are inferior to glass, which is described in detail in the comparative article What is Better Protective Glass or Film.

protective film

Read also Best Brands for Tempered Glass Screen Protector


On sale there are tempered glasses with a thickness of 0.26, 0.33 and 0.5 mm. In theory, as the thickness increases, the protective properties also grow. In practice, mechanical energy is absorbed in the same way. Except that the wear resistance of the glass is 0.5 mm higher in comparison with the options of a smaller thickness. Also, the thickness of the glass does not affect the sensitivity of the sensor.

tempered glass thickness

It is worth noting that glass often negatively affects the ultrasonic fingerprint scanner. The increase in thickness interferes with the reading of the fingerprint, which is solved only by buying a glass device certified by the manufacturer or an option with a cutout for the reading place. In the first case, the glass will cost more, in the second it is cheaper, but worse in aesthetic terms.

Surface Type

Tempered glasses with glossy, matte and combined surfaces are available.

Glossy glass does not affect the brightness and color reproduction of the screen. At the same time, scratches on such a protective surface are visibly better. The surface also reflects a concentrated stream of light better, which causes glare.

Frosted glass is less common, since the brightness is partially reduced after installation. The image becomes somewhat grainy, which increases eye fatigue. At the same time, scratches and glare on the glass are less noticeable.

There are also combined-type glasses that combine the advantages of a glossy and matte surface.

It is preferable to choose a glossy or combined type of glass.

Read also What is UV Tempered Glass?


This parameter affects the light transmission of the screen through the glass. The greater the transparency, the less light will be retained by the tempered glass screen protector. Most glasses have a transparency level of 92-95%. There are also glasses with transparency of up to 98-99%.

tempered glass transparency

It is preferable to choose glass with maximum transparency. Otherwise, you will have to increase the base brightness level, which will accelerate the battery discharge.

transparency of protective film


Each tempered glass is made for a specific smartphone model, which takes into account the dimensions of the screen, the aspect ratio and the cutouts for the elements built on the front side.

In tempered glass screen protectors, the edges at the ends are beveled, as indicated by the 2.5 D prefix in the name. The presence of rounding eliminates the possibility of a finger cut during operation, visually the glass is not so noticeable, and even less likely to catch and undermine the glass on a sharp edge.

Also, there are 3D glasses on sale with bends that repeat the shape of a smartphone. Basically, such glasses are designed for devices with a waterfall screen, where the faces completely or partially go to the side.

It is important to buy the glass corresponding to the smartphone model used. If there are no suitable glasses for such a model, it is worth considering similar models, being aware that there may be discrepancies during installation.

Coating and Spraying

Most glasses contain a light or active oleophobic coating. Thanks to the coating, fewer stains are formed on the surface during use, and moisture concentrates and flows down in the form of drops. At the same time, such a coating is not durable and is erased after 1-2 weeks. For the restoration of oleophobic spraying, appropriate gels are available on sale.

There are also glasses with a UV coating that reduces the effect of color on the eyes in a certain spectrum.


What should I look for when buying a tempered glass screen protector?

On the value of the strength, transparency and shape of the glass. It is also worth exploring additional features such as blue filtering or glare suppression.

How do I choose the best tempered glass?

It’s worth asking other owners of the phone model you’re using what screen protectors they’ve used and how successfully. Based on the collected reviews, choose the appropriate glass. Often customers leave a review of the purchase. The most valuable reviews left after time, not immediately after purchase.

How can you tell the quality of tempered glass?

You can look for customer reviews or videos showing product quality.

Which tempered glass is best matte or glossy?

If display quality is an important criterion, then glossy glass. If you want to suppress glare, then frosted glass. It is not easy to find frosted safety glass on the market.

What is the best thickness for a glass screen protector?

Any thickness will do. The most common thickness of glass is 0.5 mm.

Which is better 9D vs 9H tempered glass?

9D glass is better because it contains various filters and several additional coatings, such as oleophobic. However, it is very difficult to find real 9D glass. Usually, 9D glass is a marketing gimmick or fake.

What is 9D tempered glass?

Tempered glass consists of several layers and has a hardness of 9 on the Mohs scale. It is not easy to find such types of glass and the name hides ordinary glass with a hardness of up to 5-6 points.

Is 9H tempered glass good?

Yes, it is strong and reliable glass. However, the 9H value does not always mean high quality and strong glass. There are plenty of fake tempered glass with lower strengths on the market.

What is the best screen protector 2021?

The best protective coating is tempered glass. Even the most common and cheapest glass is stronger than film.

Can tempered glass damage your screen?

Damage to the screen is unlikely. In the case of damage, the tempered glass cracks and is held in place by an additional fixing film. The corners of the glass are not sharp, so the tempered glass cannot cause damage to the screen.

Are all screen protectors tempered glass?

A wide variety of protective coatings are available for sale. Hardened glass, thin films, liquid glass, and a hybrid of plastic and glass are available. The combination of the composite contributes to the strength characteristics. Therefore, such glass is less susceptible to damage upon impact, but scratches faster.


The article describes in detail how to choose a tempered glass screen protector for a smartphone. The collected recommendations will help you choose the optimal tempered glass in combination with useful properties that will not worsen the performance of the sensor, brightness and color reproduction.

What questions do you have? Ask in the comments below this article.

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About the author 

Alex Gustman

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