Worked very good, until I started to use the new FF feature "Tab Group" (built-in, not a plugin) - "Sort Tabs" scrambles the tabs and ignores the groups.

Seamlessly sorted a thousand of open tabs.
However, I agree with other commenters that sorting by domain and dark theme support would've been nice. Otherwise, a nice extension that does exactly what it's said to do.

Works well for me. Only wish I could sort the tabs by domain instead of just url.

Works well, no issues. Useful for clearing down tab-overload after a heavy session. An idea for an enhancement (would earn 5 stars) - provide the option to sort by just the last two parts of the domainname - so that eg. docs.nginx.com, www.nginx.com and nginx.org would all be placed together.