NOTICE: Moving forward, support articles will be updated and housed on the AddThis Academy. For the most up to date articles, as well as other support documentation, please visit us at www.addthis.com/academy. If you need additional help, you can submit a help ticket via the support link in the footer. Thanks!
If you are using AddThis on a https:// page you will need to make some small changes.
In the code of the widget replace:
That's it. All features will continue to work the same.