Window Focus Bypass

Stop websites from noticing that you switched to another window, tab or app. The page always thinks it is visible and focused.

1. Bookmarklet easiest

Show the bookmarks bar: ⌘⇧B (Mac) / CtrlShiftB (Windows).
Drag this button onto the bookmarks bar:

🙈 Focus Bypass

Then click the bookmark on the page where you want it. It stays active until you reload the page. Works almost everywhere; a few pages start watching focus before you can click the bookmark – use the userscript there.

2. Userscript most reliable

Install the Tampermonkey or Violentmonkey extension.
Click the button and confirm the install:

Install userscript

Runs automatically on every page, before the page's own scripts, and updates itself. Switch it off in Tampermonkey with one click.

3. Chrome extension per-site switch

Download the repository and unzip it.
Open chrome://extensions and turn on Developer mode (top right).
Click Load unpacked and pick the extension folder.

Pin it to the toolbar, then click its icon on any site and switch it on. Chrome asks for access to just that site (or to all sites, if you choose that). Tabs where it is on show an ON badge.

4. Console no install

Click Copy script.
On the target page, open the console: ⌥⌘J (Mac) / CtrlShiftJ (Windows).
Paste and press Enter. (Chrome may first ask you to type allow pasting.)

(() => {
  const FLAG = Symbol.for('windowFocusBypass');
  if (window[FLAG]) return;
  Object.defineProperty(window, FLAG, { value: true });

  const getter = (proto, prop, value) => {
    try {
      Object.defineProperty(proto, prop, { configurable: true, enumerable: true, get: () => value });
    } catch {
      /* not configurable on this page */
    }
  };
  getter(Document.prototype, 'hidden', false);
  getter(Document.prototype, 'webkitHidden', false);
  getter(Document.prototype, 'visibilityState', 'visible');
  getter(Document.prototype, 'webkitVisibilityState', 'visible');

  const realHasFocus = Document.prototype.hasFocus;
  try {
    Document.prototype.hasFocus = function hasFocus() {
      return true;
    };
  } catch {
    /* ignore */
  }

  const isPageLevel = (t) => t === window || t === document || t === document.documentElement || t === document.body;
  // Element blur/focusout is swallowed only when the whole window lost focus,
  // so moving between fields on the page keeps working.
  const windowLostFocus = () => {
    try {
      return !realHasFocus.call(document);
    } catch {
      return false;
    }
  };

  const stop = (e) => {
    if (isPageLevel(e.target) || windowLostFocus()) e.stopImmediatePropagation();
  };
  for (const type of ['blur', 'focusout']) window.addEventListener(type, stop, true);

  const stopVisibility = (e) => e.stopImmediatePropagation();
  for (const type of ['visibilitychange', 'webkitvisibilitychange']) window.addEventListener(type, stopVisibility, true);

  const stopLeave = (e) => {
    if (!e.relatedTarget && isPageLevel(e.target)) e.stopImmediatePropagation();
  };
  for (const type of ['mouseleave', 'mouseout', 'pointerleave', 'pointerout']) window.addEventListener(type, stopLeave, true);

  // Inline handlers (window.onblur = …, document.onvisibilitychange = …): drop any already set
  // and ignore new ones, so even a late injection silences them.
  const muteHandler = (obj, prop) => {
    try {
      obj[prop] = null;
      Object.defineProperty(obj, prop, { configurable: true, get: () => null, set: () => {} });
    } catch {
      /* ignore */
    }
  };
  for (const prop of ['onblur', 'onfocusout', 'onvisibilitychange', 'onmouseleave', 'onmouseout']) {
    muteHandler(window, prop);
    muteHandler(document, prop);
  }
  if (document.readyState !== 'loading') console.info('Window Focus Bypass: focus changes are now hidden from this page.');
})();