Many people requires a screen shot of the web page or website for the different kind of reasons. Web Developer and SEO users take screen to debug their work or want to send the render info the page to the other persons.
Some person take a screen shot to save their work and want to compare or check their work later. Many offline software also available to take a snap shot of the web page with vary good features to point some arrow, rectangle and many things but it required to download the software.
But here i am writing several online tools that allow the user to take webpage screenshot. This tools will allow you to take screen shot of any web page and allow to save or download the page locally.
1) web-capture
3) thumbalizr