Is Duplicate Content responsible for the strong fluctuations in the indexed pages of my website?

If you notice continuous fluctuations in the number of the indexed pages over a longer period of time then the reason for, or a sign thereof, could very well be Duplicate Content.

Strong fluctuations and a noticeable up and down in the number of indexed pages could point towards a Duplicate Content problem

In order to evaluate these fluctuations and figure out whether there is a Duplicate Content problem, you will need to run an OnPage-Analysis for the specific domain.

If you want to figure out how you can get to the bottom of such ups and downs and get some initial ideas for evaluations, please see: