Wraith
A responsive screenshot comparison tool
...Wraith uses a headless browser to create screenshots of webpages on different environments (or at different moments in time) and then creates a diff of the two images; the affected areas are highlighted in blue. There are two main modes for using Wraith, 'capture' mode and 'history' mode. Wraith has some built-in JavaScript and configuration file templates for you to get started with right away. If you wish to take screenshots of a component rather than the entire page, use casperjs and pass a selector along with your paths. In the 'component' example config, you can see how we specify a component name, domain path and selector we want to capture. ...