I had some old game controllers that plug to USB port that I wanted to test.
How to test game controllers connected to a PC? Preferably without installing new app I would be just using few times and forget to my PC.
Nowadays you can test the joystick using web browser thanks to HTML 5 GamePad API. For example Geo-FS flight simulator recommends testing the joystick with Gamepad Tester and Debugger available at https://gamepad-tester.com/. It worked well for me with Chrome and FIrefod web browsers running on Windows 10 PC. I used it to rest the joystick and gamepad I had. This is also useful for debugging broken controllers, experimental hardware, and more. Multiple gamepads can be connected to a computer at once. This displays them all, and their current state.
If your browser implements the gamePad API properly, this should work well. Unfortunately that does not yet work in all systems on all browsers because the Gamepad API is still inconsistent across browsers and OSes.
Some things to check if you have problems:
Is the device plugged in / connected via bluetooth
Press some buttons. On some devices, only certain buttons will wake up the gamepad API (the shapes on PS3 controllers, for instance)
Close other apps that may be using the gamepad
Try restarting your web browser
Other similar test tools: