New version of pgAdmin 4 is based on QT5. When you install pgAdmin 4 on Windows computer with a high-density display you may see that letters are too small.

Solution is to send one parameter to QT engine. It will handle DPI in different way.

Open PowerShell and go to directory with pgAdmin. Then launch application with parameter:

cd "c:\Program Files\PostgreSQL\9.6\pgAdmin 4\bin"
.\pgAdmin4.exe -platform windows:dpiawareness=0

You can persist the configuration by creating qt.conf. Start PowerShell as Administrator.

Click Windows Start menu and type: powershell. Then right-click and select the option: Run as Administrator.

Go to directory with pgAdmin and create the file:

cd "c:\Program Files\PostgreSQL\9.6\pgAdmin 4\bin"
notepad qt.conf

Write there following content:

[Platforms]
WindowsArguments = dpiawareness=0

Save the file and start pgAdmin 4 and enjoy new font size.

Note: make sure that the file name is just qt.conf. Notepad could add .txt file extension when saving the file directly from Notepad.