OS Details

Xiaomi Redmi Note 9 Pro has been launched in April 2020.
Xiaomi Redmi Note 9 Pro have Android 10.0 ; MIUI 11

Screen Dimensions

Xiaomi Redmi Note 9 Pro screen size is 6.67 inch with ~ 84.5% body ratio of actual device size. Physical dimensions for Xiaomi Redmi Note 9 Pro device is 6.53 x 3.02 x 0.35 INCH or ( 165.8 x 76.7 x 8.8 MM).

Displaying of Units are in this order "Height x Width x Thickness"

Screen Pixel Density and CSS Pixel Ratio

"Pixel" is smallest unit/element of any display.

The total number of pixels that fit into an inch is referred to as "Screen Density" or "Pixel Density" and it measured as "Pixels Per Inch".
Pixel Desnsity have limits to display Pixels Per Inch depends on different screen sizes. When number of pixels per inch increases than it's screen-size limit, the Display resolution will increase but actual device width/height in pixels remain same. Actual device pixels are known as Device Independent Pixels or CSS Pixel Ratio.

Xiaomi Redmi Note 9 Pro resolution is 1080 x 2400 ^PX with ~ 395 pixel desnsity.
Xiaomi Redmi Note 9 Pro viewport size is 393 x 873 ^PX with ~ 144 actual pixel density, which means it have 2.75 xxhdpi display pixel density.

Screen Resolution and Viewport

The sum of pixels which are displaying on a device is called as "Screen Resolution". and sum of actual pixels of any device is reffered to as "Viewport".

Xiaomi Redmi Note 9 Pro have 6.67" physical screen size and its resolution is about 1080 x 2400 Pixels with approximately 395 PPI pixel density. Xiaomi Redmi Note 9 Pro has viewport size 393 x 873 Pixels and its pixel ratio is about 2.75.

For better understanding screen actual sizes, viewport sizes, display resolution and about their density click here.

CSS Media Queries

Xiaomi Redmi Note 9 Pro css media queries will help developers to write styles specifically for Xiaomi Redmi Note 9 Pro. Here are details:

Xiaomi Redmi Note 9 Pro Media Queries (In terms of Mobile only)

@media only screen and (min-width: 393px) and (max-width: 767px) { /* Your Styles... */ }

Xiaomi Redmi Note 9 Pro Min-Width Media Queries

@media only screen and (min-width: 393px) { /* Your Styles... */ }

Xiaomi Redmi Note 9 Pro Min-Height Media Queries

@media only screen and (min-height: 873px) { /* Your Styles... */ }

Xiaomi Redmi Note 9 Pro Landscape Media Queries

@media only screen and (min-width: 873px) and (orientation: landscape) { /* Your Styles... */ }

Xiaomi Redmi Note 9 Pro Portrait Media Queries

@media only screen and (min-width: 393px) and (orientation: portrait) { /* Your Styles... */ }

Xiaomi Redmi Note 9 Pro Device Width Media Queries

@media only screen and (min-device-width: 393px) and (orientation: portrait) { /* Your Styles... */ }
@media only screen and (min-device-width: 873px) and (orientation: landscape) { /* Your Styles... */ }

Xiaomi Redmi Note 9 Pro Retina Media Queries

@media
  only screen and (-webkit-min-device-pixel-ratio: 2.75),
  only screen and (   min--moz-device-pixel-ratio: 2.75),
  only screen and (     -o-min-device-pixel-ratio: 2.75/1),
  only screen and (        min-device-pixel-ratio: 2.75),
  only screen and (                min-resolution: 395dpi),
  only screen and (                min-resolution: 2.75dppx) { 
    /* Retina styles here */
}
                                

Retina is actually based upon device pixel ratio. Devices mostly have 2x or 3x display so you can use general retina media queries to display high resolution content on all kind of devices. Retina 2x and Retina 3x media queries given below:

Retina 2x Media Query (for all 2x resolution supported devices)

@media
  only screen and (-webkit-min-device-pixel-ratio: 2),
  only screen and (   min--moz-device-pixel-ratio: 2),
  only screen and (     -o-min-device-pixel-ratio: 2/1),
  only screen and (        min-device-pixel-ratio: 2),
  only screen and (                min-resolution: 192dpi),
  only screen and (                min-resolution: 2dppx) { 
    /* Retina styles here */
}
                                

Retina 3x Media Query (for all 3x resolution supported devices)

@media
  only screen and (-webkit-min-device-pixel-ratio: 3),
  only screen and (   min--moz-device-pixel-ratio: 3),
  only screen and (     -o-min-device-pixel-ratio: 3/1),
  only screen and (        min-device-pixel-ratio: 3),
  only screen and (                min-resolution: 384dpi),
  only screen and (                min-resolution: 3dppx) { 
    /* Retina styles here */
}
                                

Xiaomi Redmi Note 9 Pro Specifications

• Launch Date April 2020
• Android 10.0
• Physical Screen Size 6.67 INCH
• Resolution 1080 x 2400 PX
• Viewport Size 393 x 873 PX
• Pixel Density 395 PPI
• Device-Independent Pixels 144 PPI
• Pixel Ratio 2.75 xxhdpi
• Width 1080 PX
• Height 2400 PX
• Device Width 393 PX
• Device Height 873 PX
• Dimensions 165.8 x 76.7 x 8.8 mm (6.53 x 3.02 x 0.35 in)
• Weight 209 g - 7.37 oz