To change your slide size in Adobe Captivate from 1366×768 to 1280×720, start by opening the project where you need the adjustment. Once your project is open, navigate to the ‘Properties’ tab, typically located on the right side of the Captivate interface. In the Properties panel, you’ll find the ‘Rescale Project’ button – click on it. This opens a dialog box where you can enter the new dimensions for your project. Input 1280 in the width field and 720 in the height field to set your project to the 1280×720 resolution. After entering these dimensions, Adobe Captivate will prompt you to decide how to adjust the existing content. You can choose to let Captivate automatically scale the content or opt to manually adjust it yourself. If your project contains detailed designs or specific layouts, manually adjusting might be the better choice to ensure everything aligns as expected. Once you’ve rescaled the project, it’s crucial to go through each slide to make sure all elements, including text, images, and interactive components, are properly aligned and appear correctly. Finally, remember to save your project to keep the changes. Keep in mind that changing the slide size can significantly affect the layout, so it’s important to carefully review each slide after resizing.

With the new version you can only create responsive projects, which means that the exact size has not the same meaning, since items will be rearranged to fit the browser resolution. You are not able to change the desktop slide size, but it has almost exactly the same width/height ratio as what you wanted. The result will be OK.