Apart from tons of other features, Web developer toolbar[1] has this functionality built-in. It allows us to save our own dimensions too. Of course, if one wan

Apart from tons of other features, Web developer toolbar[1] has this functionality built-in. It allows us to save our own dimensions too. Of course, if one wants just the 're-sizing' capability, then this bookmarklet will sure help. [1] - https://addons.mozilla.org/en-US/firefox/addon/web-developer/?src=search https://addons.mozilla.org/en-US/firefox/addon/web-developer...