How to remove white border in PDF preview?

I was searching to resolve the same problem, I use accessabillity black page and the border is annoying green, 
Finally I found the solution to review my Docs without border lines, 
go to Edit>Preference>Page Display> Page Content and Information> uncheck the box of Show trim, art, and bleed boxes, Hope that helps!

The solution I found in my versin of Adobe Acrobat is to go to the Organize Pages section for editing pdfs, select all pages, right click and select "Crop Pages", then select Remove White Border.  I couldn't do it by doing  the "Edit PDF -> Crop Pages" route.

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Ah, I didn't even see that. But, yes, I do see a white line. I imagine it's there to show where the edge is, when pages are the same grey as the window. Or someone's idea of decoration, developers do like to impress us with this sort of thing. It's a light grey as it turns out, not white, and for me it's only on the top and left sides. No option to turn it off.

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There isn't a global setting that does that. You will need to crop out the white margins from your files, either individually or in an Action, if you have Acrobat Pro.