Tried to access it this AM for reference and got some "network solutions" page that appears to offer stuff for sale (didn't follow any of the links on the page, so don't know for sure). Got the same trying multiple pages.

Anyone else having the same problem?

Looks like it's down. Hopefully, just temporary.

It's not completely down for me, but I get a security warning that the certificate is invalid using Firefox (with the option to connect anyway), and Edge just refuses to connect entirely.

For some reason, Chrome connects just fine and also shows a valid certificate.

Try clearing Firefox's data for the site (go to sheldonbrown.com, click on the padlock icon by the URL afterwards, then click on "clear cookies and site data"). That may clear the problem.

Did that, and got zero security warnings/mixed content warnings/etc . . . . with my Firefox install when I visited the site about 15 min ago. Seems to be back to normal.

A whois lookup shows the domain details were updated today, so maybe a change in webhost or similar? Https isn't working for me atm, the site is responding but not all the content is there.

I just got a security warning as well. Safari on an iPad.

The sheldonbrown.com facebook page posted that they are changing servers and things should be back to norming in 24 to 48 hours.

I was on it on yesterday and no issues so glad to hear it is just a server switch! That info is too good and important to go away.

it seems to be fine now... i hit all three links i have stored, and they popped right up.

YAY!