Instructions:
1. Click Invite Friends on whatever you are inviting people to
2. In the dropdown next to the search box, click Search All Friends
3. Scroll ALL the way down until names stop loading (I found it easy to click the first name and then hold down the spacebar or Page Down button)
4.
For EVENTS Copy this code:
javascript:elms=document.getEl
ementsByName("checkableitems[]");for (i=0;i.type="checkbox" )elms.click()}

For PAGES Copy this code:
javascript:var inputs = document.getElementsByClassName('uiButton _1sm');
for(var i=0; i inputs.click();
}

For Chrome:
5. Press (CTRL+Shift+J) for WINDOWS or (Command+ Option+J) for MAC on your keyboard.

6. Paste the code into the box at the bottom and press enter (next to the blue ">")
7. For large friends list, this may utilize all your resources and will cause the page to freeze and be unresponsive. Just wait a few minutes until all the names get selected.

For Firefox:
5. Press (CTRL+Shift+K) for WINDOWS or (Command+Option+K) for MAC on your keyboard
6. Paste the code into the box at the bottom and press enter (next to the blue ">>").
7. For large friends list, this may utilize all your resources and will cause the page to freeze and be unresponsive. Just wait a few minutes until all the names get selected.


For Safari:
5. Go to Preferences - Advanced - check "Show Develop menu in menu bar" and close the preferences window.
6. Go to Develop - Show Error Console (or Command + Option + C)
5. Paste the code into the box at the bottom and press enter (next to the blue ">").


For Internet Explorer:
5. Press F12 on your keyboard
6. Click the "Console" tab
7. Paste the code into the box at the bottom and press enter.
8. For large friends list, this may utilize all your resources and will cause the page to freeze and be unresponsive. Just wait a few minutes until all the names get selected.