Detect Internet Explorer browser

Look for document.documentMode, which only Internet Explorer defines.

JavaScriptBrowser · DOM Version 1.0.0 · MIT · .md

function isInternetExplorer() { return 'documentMode' in document; }

Usage

isInternetExplorer(); // → false

Lines marked → were executed in headless Chromium against the markup above, and each result was compared with the value shown. Lines marked e.g. are illustrative.

Know the limits

• Microsoft retired the Internet Explorer 11 desktop application in June 2022. Keep this only to show an upgrade notice in legacy intranets.
• Detect the feature you need instead of the browser, such as "IntersectionObserver" in window.

The function above is the code the usage lines run. It does not validate its arguments; add checks where it receives untrusted input.

Keep exploring

• Check if a given DOMRect is contained within another DOMRect — True when the target lies inside the container or on its edges.
• Check if two DOMRects intersect — Two rects intersect when they meet on both axes.
• Compare two DOMRects for size and position match — Compare x, y, width and height exactly.