We have mentioned about JavaScript code and Greasemonkey Script to select all friends when suggesting. It’s really easy to sent invitations to all your friends to a group or page on Facebook. But Facebook seem to have new updates and both Javascript code and the script don’t work with latest Facebook.
Technoskillonline has found a Google Chrome extension which really works. Just go to the extension page and install it on Chrome browser. You can select all your friends when suggesting by clicking on toggle all.

I tried to search a similar add-on for Firefox but cannot find any of such. Firefox users can either switch to Chrome for using this feature or download this firefox add-on which enables to use Chrome extension on Firefox.
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