This article teaches you how to increase or decrease the size of items (for example, applications) on your Android screen by reducing or increasing the default dots per inch (DPI) of your device.
This is a standard option in the “Settings” menu of any Android with Nougat (7.0) or later, although you can also change the DPI in Marshmallow (6.0) and earlier versions using a computer and Android Studio Developer Kit.
Keep in mind that it is not possible change the actual resolution of your Android, which is determined by the screen itself.
Also Read : How to Split Screen On Android
On Android Nougat and earlier versions
Open the menu Image titled Android7settingsapp.pngSettings of your Android. To do so, tap the Settings app icon . It is the one that looks like a colored gear.
You can also slide the screen down and tap the gear icon in the drop-down menu that appears.
Scroll down and tap About phone . It is one of the last options in the Settings menu .
If you’re using a Samsung Galaxy, tap Display .
Scroll down and tap “Build number.” It’s at the bottom of the “About phone” menu.
If you’re using a Samsung Galaxy, tap Screen resolution in the “Display” menu.
Tap the “Build Number” option seven times. Doing so will unlock the Developer menu , from which you can change the resolution of your Android.
Once developer mode has been enabled, the message “You are now a developer!” Will appear.
If you are using a Samsung Galaxy, here you can select a screen resolution by touching the slider and dragging it to the left or right to reduce or increase the resolution.
Tap the “Back” button. Doing so will take you back to the “Settings” page.
If you’re using a Samsung Galaxy, tap APPLY in the upper right corner of the screen. The new resolution will be applied immediately.
Tap Developer Options . This option is near About phone .
On some Android models, you have to scroll up or down to find this option.
Scroll down and tap Minimum width . It is one of the last options on the page. Tapping it will open a pop-up window.
This option is at the bottom of the “Developer Options” page, so you will have to scroll down several times to reach it.
Enter a new width. Tap the text field in the middle of the pop-up window, and then type a new width to change the resolution.
The larger the number, the smaller the items on the screen (for example, text, icons, etc.) appear.
You can choose a width of at least 120 pixels and maximum 640 pixels.
Touch OK . It’s at the bottom of the pop-up window. Doing so will adjust the resolution of your Android.
On Android Marshmallow and earlier versions
Download and install the Android Studio Developer Kit. The Studio Developer Kit (SDK) will install something called the Android Debugging Bridge, which will allow you to run commands on a connected device. Go to https://developer.android.com/studio/index.html , click the green button that says DOWNLOAD ANDROID STUDIO, and then do the following:
Windows : Check the “I have read and agree …” box, click the blue DOWNLOAD button , double-click the downloaded EXE file, follow the on-screen instructions, open the Android SDK, and then follow the setup instructions.
Mac : check the “I have read and agree …” box, click the blue DOWNLOAD button , double click the downloaded DMG file, check the software if necessary, follow the instructions on the screen, open the Android SDK and then follow the setup instructions.
Enable USB debugging mode on your Android. USB debugging mode will allow you to make changes to your device using your computer’s command line.
If USB debugging mode is already enabled, skip this step.
Connect your Android to the computer. Plug the USB end of your Android’s charger cable into one of your computer’s USB ports, then plug the other end into your Android’s charging port.
The charging port is usually on the bottom of the device.
Open your computer’s command line program. The command line program for Windows is Command Prompt and the one for Macs is Terminal:
Windows : openImage titled Windowsstart.png Start , type símbolo del sistemaand clickImage titled Windowscmd1.png Command prompt at the top of the menu.
Mac : openImage titled Macspotlight.png Spotlight , type terminaland double-click theImage titled Macterminal.png Terminal at the top of the search results.
Check the current resolution of your Android. To find out the current resolution (or “density”), follow these steps: 
Write adb shelland press ↵ Enter.
Write dumpsys display and press ↵ Enter.
Check the number to the right of the word “density” (for example, density 420 (403.411 x 399.737)).
Change the resolution. Write making sure to replace resolution with the three digits of the desired resolution and press . wm density resolución && adb reboot↵ Enter
If you enter a number greater than your current resolution, items on the screen will appear smaller. If you enter a smaller number, the items on the screen will appear larger.
Android resolutions can generally range from 120 to 640 pixels, so the resolution you choose should be within those parameters.
Restart your Android if necessary. To do this, press and hold the power button on your Android until a menu appears and select the option to Shut down or Restart .
If your Android changes the resolution immediately after entering the command, then it will not be necessary to restart it.
There are many applications to change the DPI of your phone, but your Android must be rooted in order to use them.
After changing the resolution, your Android’s on-screen keyboard may look distorted. To fix this, you can install a keyboard that can adjust to the new DPI settings (eg GBoard).
In some cases, when changing the DPI, there may be compatibility issues when downloading applications from the Google Play Store. In that case, you can go back to the original DPI settings, download the app, and change the DPIs again.
Although you can modify the screen resolution to increase or decrease the size of the elements, it is not possible to increase the definition beyond the maximum resolution of your Android (for example, from 720p to 1080p) since the definition depends on the physical screen of the device.