We have a downloads library containing about 22,000 items (pages) and for each of the pages, there is a section of screenshots showing the download in action.
Currently, we can't go through almost 110,000 images and add unique ALT descriptions so what we have done it simply left the ALT attribute blank (alt="").
Would it be beneficial to add something like alt="Screenshot 1", alt="Screenshot 2"... etc?
Or maybe "alt="Screenshot 1 of Title of Download"... etc.
We don't want to over-do SEO and flag up any filters.
Or is it OKAY to leave these ALT attributes blank in this situation?
Your comments, thoughts and suggestions are greatly appreciated in advance.