Image Resizer is a free Firefox add-on designed for quick and easy image resizing. It allows users to adjust image dimensions simply by holding down the right mouse button (RMB) and dragging to resize. The functionality includes restoring images to their original size with a right-click, and users can also zoom in and out using the mouse wheel while holding RMB. This tool is particularly useful for graphic designers and anyone needing to manipulate images directly in their browser without additional software.

The add-on comes with specific configuration instructions to enhance user experience, such as ensuring that JavaScript settings allow for context menu manipulation. However, users should be aware of known issues with certain websites where image resizing may not function correctly due to site design or conflicts with other add-ons. Overall, Image Resizer offers a straightforward solution for image editing directly within Firefox.