I apologize for the frustration. I understand how important it is to have the Constant Contact page load in a timely manner. We've heard our customers mention slowness in the system and we've reported this feedback to our engineers so that we are looking into any issues that are occurring on our end.
Constant Contact is compatible with the most recent stable (non-beta) releases of these browsers:
Since you mentioned that you have tried most of these browsers and the issue is still present I would suggest that you run a speed test on your Internet Service Provider. The Constant Contact website uses more bandwidth than normal websites, like Yahoo and Google. This is because using Constant Contact is similar to running Word in your browser. Low upload and download speeds can cause time out errors and slow page loading even if other sites work just fine. As a side note, wireless 3G/4G, and Satellite connections are greatly affected by weather. Rain, snow, or wind can also create bandwidth issues. If the download speed is 3+MB, and or the upload is 1+MB, you should have enough bandwidth to run our site without issues. There are free services online to run speed tests, a quick Internet search for Internet speed tests should help you to find one. Then you want to confirm that the upload and download speed is meeting our requirements. I hope this post is helpful to you and please let us know if you have any questions.