Originally Posted by enitro
is there any side by side feature that I can see the first 10 pages on one side and metadata of the books on the other side with one click
There's no native side by side comparison tool/feature in Calibre.
How I do it is, I first use the Find Duplicates plug in to find and remove exact binary dupes. No need to visually compare those.
Then I use the "Open With" plug in and map opening books with Calibre's ebook reader to a Keyboard Shortcut and just visually compare them that way.
You could also probably utilize the plug in to pass files to a diff tool or visual comparison tool if you can find one that supports opening files via command line arguments and supports whatever formats you're dealing with.