The window pane test
Whether you’re kneading by hand or with a mixer, the amount of kneading time will vary depending on what you’re baking, how fast you knead, etc. Instead of relying on the clock, it’s best to know what you’re looking for in a properly kneaded dough.
The dough should appear smooth on the outside and be elastic. The best way to test elasticity is with the “window pane” test. Pinch off a piece of dough and hold it between your fingers. Slowly stretch the dough and watch what happens. Dough that has only been kneaded a few times will break apart immediately. Give it some more time. Dough that has been sufficiently kneaded will stretch easily and become thin enough that you can see light through it, like a window pane.