Owners of the popular Xiaomi Redmi Note 9 model often wonder about the real-world specs of their display, especially when it comes to watching high-quality video content or installing specific games.The standard specification states that the device is equipped with a high-end video display. IPS-full-matrix HD It's resolution-based, but software can make adjustments to the image that's being displayed, and understanding the exact parameters is necessary to calibrate the fonts, to customize the interface, or simply to satisfy the user's technical curiosity.
The actual pixel values can be determined in a number of ways, from simple viewing of the characteristics in the menu to the use of engineering codes. It is important to distinguish between the physical resolution of the matrix and the software resolution, which can change when you turn on the “increase” mode or use third-party launchers. In this article, we will discuss in detail all available verification methods so that you can get comprehensive information about your gadget without the need to install questionable software.
Physical resolution is a constant characteristic, laid down by the manufacturer, while software settings can dynamically change the density of dots per inch. For the Redmi Note 9, this is especially true, since the MIUI system has many hidden settings for developers. Let's look at how to access this data as safely and efficiently as possible.
Standard display characteristics Redmi Note 9
Before we go to technical checks, it is worth refreshing the official data provided by Xiaomi. the Redmi Note 9 model, released in 2020, received a 6.53-inch DotDisplay display. The basic resolution is 2340×1080 pixels, which corresponds to the Full HD+ format. The aspect ratio in this case is classic for modern smartphones – 19.5:9.
The pixel density (PPI) on this screen reaches 395, which provides a fairly clear picture even when close inspection. Color reproduction is configured to the standard sRGB spectrum, although you can choose more saturated or warm colors in the color settings. However, you should not rely only on marketing data, since the actual software resolution may differ due to system limitations or user modifications.
It's important to understand that screen resolution isn't the only feature that affects image quality. Update frequency, brightness and matrix type also play a role, but it's the number of pixels that determines the interface's detail. In standard operating mode, the system uses native resolution, balancing picture quality with power consumption.
⚠️ Note: Don’t confuse screen resolution with pixel density (DPI). Change of change DPI In the developer settings, changes the size of interface elements, but does not add a physical pixel to the matrix.
Checking through the system settings menu
The easiest and safest way to find out the current display settings is to look into the system menu, go to Settings, scroll down and select About Phone, which displays basic information about the model, the MIUI version, and, in some versions of the firmware, the screen resolution. If this menu is missing, use the developer menu.
To activate the hidden menu, you need to go to Settings → About the phone and seven times in a row quickly click on the version MIUI. After the notification "You became a developer" will open access to advanced features. → For developers, find Smallest Width, which shows the current density of the interface in dp (density-independent pixels).
Although this parameter doesn't show resolution directly in pixels, it's directly related to it.Knowing the base resolution and the current width in dp, you can calculate the zoom ratio.The standard value for the Redmi Note 9 is usually around 392-411 dp. Changing this number will cause the fonts and icons to change size, which can be useful for people with poor vision.
☑️ Checking screen settings
It's worth noting that in some MIUI shells, resolution information may be hidden in All Specifications, so if you don't find 2340x1080 strings there, it's hiding that data to make the interface easier, and you'll have to use more advanced diagnostic techniques.
Use of engineering menus and codes
To get more technical information, users often use an engineering menu that is hidden from the user, which can be entered through a standard dial by dialing the combination ##6484##. This will open the CIT (Customer Information Test) menu, where you can check the operation of all components, including the display.
In the test menu, you need to select the item associated with checking the display (usually called Display or Screen), where you can see not only the current resolution, but also check for broken pixels, uniformity of the backlight and touchscreen, which is a great way to make sure that the screen is working normally and meets the declared characteristics.
Another code that might be useful is ##4636##. It opens the testing menu, where the Phone Information or Display Information section sometimes displays technical rendering details, but on modern versions of Android and MIUI, access to this data through this code may be restricted for security reasons.
What do I do if the codes don't work?
It's safe to use engineering codes unless you change the settings inside the test menu. Just viewing the information can't harm the device, but accidentally changing the calibration settings can cause colors to be displayed incorrectly.
Application of third-party applications and utilities
If the built-in tools of the system seem to you not informative enough, you can always turn to time-tested applications from Google Play. The leader in this niche is the utility CPU-Z or Device Info HW. These programs read data directly from the system files of the Android kernel, providing the most accurate information.
Once you install an application, like CPU-Z, you start it up and go to the Device or Display tab, and you'll see the Resolution bar, which will show you the exact width and height in pixels, and it will show you the physical screen size in inches and the calculated PPI density, which allows you to check the data against the official specifications.
The advantage of using such gates is that they show not only static resolution, but also the current refresh rate, as well as information about the graphics renderer. For the Redmi Note 9, this is especially important, since the device supports various energy saving modes that can dynamically change the output parameters of the image.
- 📱 CPU-Z — Classical tool for monitoring all the characteristics of the "iron".
- 📐 Screen Resolution – a specialized application that shows the current resolution and DPI real-time.
- ℹ️ Device Info HW — Provides detailed information about the camera codec and display characteristics.
It is important to download these apps only from the official Google Play store to avoid installing malware that may ask for unnecessary permissions, most of which are free and do not require root rights for basic diagnostics.
Diagnostics through computer and ADB
For advanced users who are not afraid of the command line, the most accurate method is to use USB debugging and the ADB utility (Android Debug Bridge), which allows you to get raw data directly from the device drivers, eliminating any software distortion of the MIUI interface.
To start, you need to activate USB debugging in the developer menu (as described above) and connect the smartphone to the computer with a cable. On the PC, ADB drivers should be installed. Once connected, open the command line or terminal and enter a command to check the current resolution.
adb shell wm sizeThis command will output the current screen resolution in Physical size: 1080x2340. If the resolution has been changed programmatically, the command will show both physical and current size, and you can also find out the pixel density by the adb shell wm density command.
Using ADB gives you complete control over display parameters. You can even force the resolution to change, although this rarely makes sense for the Redmi Note 9, because native resolution is optimal. The main advantage of the method is the absolute accuracy of the data, which is independent of what the operating system interface shows.
⚠️ Attention: When using commands ADB Change the system size (wm density) without knowing the consequences can make the interface unreadable.
Comparison of resolutions in the line of Redmi Note
To better understand the Redmi Note 9’s place in the lineup, it’s useful to compare its screen to its predecessors and successors. Xiaomi often uses similar arrays in different models, but software optimization may differ. Below is a table comparing the main characteristics of the displays of popular models of the series.
| Smartphone model | Diagonal (inches) | Permission (pixels) | Type of matrix | PPI |
|---|---|---|---|---|
| Redmi Note 8 | 6.3 | 2340 × 1080 | IPS LCD | 409 |
| Redmi Note 9 | 6.53 | 2340 × 1080 | IPS LCD | 395 |
| Redmi Note 9 Pro | 6.67 | 2400 × 1080 | IPS LCD | 395 |
| Redmi Note 10 | 6.43 | 2400 × 1080 | AMOLED | 409 |
As you can see from the table, the Redmi Note 9 retained the classic Full HD+ resolution of the budget and mid-range segment of the time. The diagonal increase over the Note 8 led to a slight decrease in pixel density, but in practice it is almost invisible to the eye. The transition to AMOLED in the next generations was a more significant change than just increasing the number of pixels.
Understanding these differences helps when choosing protective glasses or films, as even a slight difference in screen shape or resolution can affect the compatibility of accessories.
💡
The Redmi Note 9 uses time-tested Full HD+ resolution, which provides a great balance between picture clarity and processor performance.
Frequent questions and problems with display
Users often experience a situation where applications show incorrect resolution or the interface looks “stretched”, this can be due to errors in the launcher cache or conflicts after the system update, in which case cleaning the Settings cache or resetting the screen settings in the developer menu helps.
Another common problem is the appearance of artifacts or stripes on the screen, which users mistakenly assume is low resolution. If the numbers are normal when checking through CPU-Z or ADB (2340x1080), and the picture is distorted, it is a physical malfunction of the matrix or plume, not a software failure.
Some users are trying to artificially increase the resolution through root rights, hoping for better quality. However, on physical screens with a fixed number of pixels, this is not possible. Interpolation of the image will only put a strain on the processor without adding real detail, and in the case of the Redmi Note 9 can lead to overheating of the device.
⚠️ Warning: If you notice a sharp change in resolution or the appearance of strange artifacts after falling or getting moisture, immediately turn off the device.