TiffOne is a browser extension that lets you view TIFF images in your browser. It scans the page, looking for images that have a "tiff" or "tif" extension, and converts those images into HTML canvases, which can then be displayed by modern browsers. TiffOne supports the multi-page functionality of TIFF images, which can be accessed by the header menu right above the displayed image. The extension provides a full screen functionality, and a print option for easy viewing and saving of the images. The extension can be turned off when not needed from the popup menu of the browser icon. TiffOne currently supports all Chromium based browsers, but it has only been tested on Google Chrome and Chromium based Microsoft Edge. The extension is only handling TIFF files, and does not collect or analyze any other data. The purpose of this extension is solely to display TIFF files in the browser, to give a convenient way to view them. Full source code can be found at: https://github.com/Vogete/TiffOne Problems, issues, feature requests can be submitted to: https://github.com/Vogete/TiffOne/issues