Sometimes automatic tests/screenshots are not enough, especially if you pick up a project that hasn't been developed with TDD in mind at first place, therefore forcing you to choose between donating your free time to develop automatic tests or manually testing each page on every global change. For one timer, it might be better to choose second option, so here is a 5 min setup for such scenario.
Step 1: First, We Will Need a List of All Pages in the Site
with [FILTER] i mean for .NET sites *.aspx, for php *php; for both maybe *.htm or *.html too, depends on the pages' structure
If you are sitting at the dev server, navigate with your evelated cmd prompt to the website folder and write
dir [FILTER] /s/b >> c:\dirlist.txt