Safari can't establish a secure connection

Since some time when opening certain pages in Safari (Mojave on iMac late 2013), I get the error: ‘can’t open the page because Safari can’t establish a secure connection’. The error occurs on certain common websites (, gmail, reddit) but not on others (, google, macpowerusers). The problem is present in all user-accounts and only in Safari (Chrome works fine). I’ve tried a number of possible solutions, but with no result:

  • Remove all website data;
  • Uninstall suspicious extensions, plug-ins, and add-ons
  • Clear Cookies
  • Adjust DNS settings
  • Disable IPv6
  • Manually set certain certificates to Always Trust
  • Reset Keychain (start with empty Keychain)
  • Updated Safari & MacOS Mojave to the latest versions

Switching to another browser does not fully solve the problem, since certain apps apparently use the Safari-engine for their login dialogs (e.g. Google Backup&Sync, Spark Email), essentially rendering these apps useless, since I cannot login.

Does anyone have any clue what could be causing this error or how to solve it, other than installing Catalina (not possible give certain 32 bit apps in use) or reinstalling Mojave (I’d rather not). Thanks a lot!

Change the url to “HTTPS://…” instead of “HTTP://…”?

1 Like

Do you have LittleSnitch running at all? I once accidentally set a weird rule in Little Snitch for Safari and had some strange messages like this in the browser.

Ever since I read @Miel’s post I have been experiencing the same thing in Safari over the last 24 hours. Usually clears itself if I count to 10 and try again. I’m laying this up to bandwidth or DNS contention (probably the latter), especially with so much more network resources being consumed these days.