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PreventPageVisibility

Block websites from knowing if you switched tabs/windows

  1. // ==UserScript==
  2. // @name        PreventPageVisibility 
  3. // @namespace   https://github.com/IceWreck
  4. // @match       *://*/*
  5. // @run-at      document-start
  6. // @grant       none
  7. // @version     1.1
  8. // @author      IceWreck
  9. // @description Block websites from knowing if you switched tabs/windows
  10.  
  11. // ==/UserScript==
  12.  
  13. // This userscript blocks the page visibility API and to some extent the old blur/focus APIs.
  14.  
  15. let events_to_block = [
  16.   "visibilitychange",
  17.   "webkitvisibilitychange",
  18.   "mozvisibilitychange",
  19.   "hasFocus",
  20.   "blur",
  21.   "focus",
  22.   "mouseleave"
  23. ]
  24.  
  25. for (event_name of events_to_block) {
  26.   document.addEventListener(event_name, function (event) {
  27.       event.preventDefault();
  28.       event.stopPropagation();
  29.       event.stopImmediatePropagation();
  30.   }, true);
  31. }
  32.  
  33. for (event_name of events_to_block) {
  34.   window.addEventListener(event_name, function (event) {
  35.       event.preventDefault();
  36.       event.stopPropagation();
  37.       event.stopImmediatePropagation();
  38.   }, true);
  39. }
  40.  
  41.  
  42. document.hasFocus = function () { return true; };
  43. document.onvisibilitychange = null;
  44. Object.defineProperty(document, "visibilityState", { value: "visible" });
  45. Object.defineProperty(document, "hidden", { value: false });
  46. Object.defineProperty(document, "mozHidden", { value: false });
  47. Object.defineProperty(document, "webkitHidden", { value: false });
  48. Object.defineProperty(document, "webkitVisibilityState", { value: "visible" });