For me this addon completely breaks browser search.
If I type a search query into the search bar it just opens a startpage container with no search term in it. If I type the same search into that window it opens another empty startpage container - etc,etc ad infinitum. No more searches possible until I disable the addon.
Shame really because I like the idea of it a lot, but it just doesn't work as it should.

Edit. Thank you for the response, I deleted my startpage search and added the official addon that you mentioned and now it seems to work as it should!!

I can't explain that one.

Incidentally both google search and bing search worked normally, startpage search has now been fixed, and ddg search first opens an empty search page but typing the search into the empty page generates the required results.

Such a great add-on! It's a powerful shot to those companies and individuals that want to exploit our personal information for their monetary gains.

I've been reading and studying the github wiki for a few days to better understand how to get this to work with Mozilla's multi-account containers and just figured out how to get the two extensions to work the way I want. At least I think I have. I have to experiment with it more.

I think you need to understand how regular expressions work to understand how this addon works. As another reviewer wrote, this is not the easiest extension to figure out, even with the links to its github wiki embedded into its configuration tabs, which makes it easy to find the exact information you want. However, the dev stated in response to an earlier review how to reach him via github to ask questions if you have questions about working with the addon and the doc is unclear to you.

This, not the "official" Containers add-on, is the true successor of Multi-Fox - but is an improved design that actually works well in tabs!

This has been awesome for our employee's and Makes multiple PeopleSoft windows actually possible once again, like they were when we used MultiFox. Thank you, thank you, and thank you.

This program is thus-far glitch free and amazingly feature-rich. The options settings are amazing.

This functionality should be STANDARD-FEATURE in Firefox. Since you can only have one Private-Session in firefox, this is perfect. Why the heck FireFox doesn't let multiple Private-Windows each have their session/self-containment, I will never know.

But this works, and works well. And you can customize the hell out of it. Very professional-level software for a mere add-on.

Doing God's work here! I LOVE keeping each tab in temp containers. I absolutely recommend this to everyone for the sake of privacy and security.

Brilliant use of containers, if only it wouldn't be so absolutely confusing. The settings here are overwhelming and I'm not sure what they do.

Amazing extension! Please keep it alive!

I love this addon! There are so many options, and it's such a huge win for web privacy! I hope many of these ideas can be integrated into Firefox itself. Brilliant work!

Edit3. I removed my previous text and changed rating from four to five stars, i found add-on that caused this annoying (duplicate tab) issue.