Safari Extension: Resize

Resize Safari Extension provides an extensive toolbar that allows you to size your browser window precisely for web development for different platforms; particularly mobile platforms.

There is a set of buttons for different types of devices (mobile landscape, mobile portrait, and laptop). Each button changes the available preset sizes to choose from. The toolbar shows the current "inside" and "outside" dimensions of your window.

There's also a reference button that brings up the reference page of devices and their resolutons.

All options are available (optionally) in the context menu with a right click.

Preset sizes are fully configurable in the settings pane.

Resize Safari costs $4.99 (which is why there is no download URL.)