Image Max URL is a versatile Firefox extension designed to help users locate larger or original versions of images across approximately 9,800 websites. It operates using about 5,600 individual rules and supports various generic engines, making it compatible with most websites. Key features include a customizable image popup, automatic detection of image galleries, and options for batch downloading images in full resolution. Users can easily configure over 300 settings to tailor the extension to their needs.

The extension works by replacing URLs and, in some cases, querying specific website APIs to fetch larger images. For instance, appending '?name=orig' to certain URLs can yield higher resolution images. While it does not replace reverse image search capabilities, it effectively complements them by focusing on revealing the largest or original images available. Image Max URL promises a user-friendly experience while maintaining privacy, as it does not contain any tracking code.