windowinnerHeight

window.innerHeight is a read-only property of the Window interface that returns the height, in pixels, of the window’s layout viewport. In practice, this represents the visible height of the page content area inside the browser window, including the horizontal scrollbar if present. It does not include the browser chrome outside the content area, such as the system UI or device chrome.

The value updates as the window changes size and can be used to adapt layouts or implement full-height sections. It is commonly read in response to resize events or orientation changes. A typical usage is to retrieve the height and adjust page elements accordingly, for example by setting inline styles or updating CSS variables:

window.addEventListener('resize', function() {

var h = window.innerHeight;

// adjust layout based on h

});

Note that on mobile devices the value can change when browser chrome (such as the address bar or toolbars) shows or hides, or with orientation changes. Depending on the precise goal, other measurements like document.documentElement.clientHeight or the Visual Viewport API (window.visualViewport.height) may be more suitable for handling dynamic viewport behavior.

Compatibility: window.innerHeight is supported by all modern browsers. It may be unavailable in very old browsers or non-browser environments.