SSHY-selainlaajennus is a Firefox extension designed to enhance the features of the Suomen Sukuhistoriallisen Yhdistyksen website. This subscription-based tool provides users with a variety of functionalities, such as the ability to zoom images in and out by 20% increments, rotate images by 90 degrees, and restore original image size and orientation. Additionally, users can generate source references and download images directly to their devices with contextual naming for clarity.

The extension also allows users to drag images for easier navigation, ensuring that image positioning remains consistent when moving between pages. Features such as always-visible functions on member pages and improved tab titles enhance usability. The extension is compatible with both public and member sections of the SSHY website, with updates continuously improving functionality, including support for English and Swedish versions.