A company that maintains several websites for various small businesses is migrating all of the sites over to new servers (they are using some sort of migration tool). They have asked me if I could write something that will visually compare each page with its migrated page to make sure they VISUALLY look exactly the same and if there are differences then flag those pages.
I have an idea how to do this but am open to other suggestions if anyone has done this before. My thought was to input a list of every home page and use a sitemap generator to get a url of every page under each site. Then I will screen capture every page using a headless browser like phantomjs. Next I will load a host file with the names/ip of all of the migrated sites and screen capture all of the new pages (same URL's just on different ip's). Finally I will use some image comparison code (maybe wraith) to compare each screenshot with its counterpart and flag ones that are different.
Seems like it could work but I would greatly appreciate others input. ((They also want me to automate form testing but I will create a separate post for that.))