Where do I find a good and free sandbox?

[valerie Inshan 5,256]

Enter "sandbox" in search and scroll down to the bottom of the list. That's where there will be the ones with small traffic. And, besides premium sandboxes which, by definition, require a paying membership plan, as far as I have experienced so far, all sandboxes are free. You may also want to choose one according to the auto return time criteria, depending on how much time you need. If it's just to open boxes, no need to look for a 6 hours autoreturn sandbox.

[valerie Inshan 5,256]

Enter "sandbox" in search and scroll down to the bottom of the list. That's where there will be the ones with small traffic. And, besides premium sandboxes which, by definition, require a paying membership plan, as far as I have experienced so far, all sandboxes are free. You may also want to choose one according to the auto return time criteria, depending on how much time you need. If it's just to open boxes, no need to look for a 6 hours autoreturn sandbox.

[PeterCanessa Oh 426]

Caledon Oxbridge, Builders Brewery, any of the NCI locations (eg; Hamnida sim).  These have the advantage of having helpers, freebies, advice and classes as well as just sandboxes.  Incidentally - they also have changing-rooms so you don't have to try on clothes in public.

If you are just trying to open boxes to get the contents out so you wear/attach/examine them then you don't need a sandbox.  Just wear the box (yes, I know that's not what you want ...), that lets you right-click and open it so you can get everything into inventory.  Then just detach the box again ;-)