Viewport

A viewport is the visible area of a web page on a user's screen. On a desktop monitor, the viewport is the browser window minus any toolbars or scrollbars. On mobile devices, the viewport is the entire screen area available to the browser. The viewport determines how much content is visible at any given moment and how that content is scaled and laid out.

Publications that ignore viewport differences look broken on certain devices. Text may be too small to read on phones, or interactive elements may overflow the screen. Since a significant share of digital content consumption happens on mobile, ensuring your publications render correctly across all viewport sizes is critical for retaining readers and maintaining a professional appearance.

FlipLink publications are fully responsive and adapt automatically to any viewport size. The flipbook viewer detects the available viewport dimensions and adjusts page rendering, control placement, and zoom levels accordingly. On wide desktop viewports, publications display in a two-page spread. On narrow mobile viewports, they switch to a single-page view with touch-friendly navigation. The [page experience](/features/page-experience-and-layout) settings let publishers choose between different layout modes, and FlipLink handles the viewport math to ensure content is always legible and well-proportioned.

A real estate agency publishes a property brochure as a FlipLink flipbook. An agent shares it with a client who opens it on their phone during a commute. The flipbook automatically adjusts to the phone's viewport, displaying single pages with swipe navigation and properly scaled images, delivering the same visual quality as the desktop version.